diff --git a/vendor/golang.org/x/sys/windows/dll_windows.go b/vendor/golang.org/x/sys/windows/dll_windows.go
new file mode 100644
index 0000000..82076fb
--- /dev/null
+++ b/vendor/golang.org/x/sys/windows/dll_windows.go
@@ -0,0 +1,415 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package windows
+
+import (
+	"sync"
+	"sync/atomic"
+	"syscall"
+	"unsafe"
+)
+
+// We need to use LoadLibrary and GetProcAddress from the Go runtime, because
+// the these symbols are loaded by the system linker and are required to
+// dynamically load additional symbols. Note that in the Go runtime, these
+// return syscall.Handle and syscall.Errno, but these are the same, in fact,
+// as windows.Handle and windows.Errno, and we intend to keep these the same.
+
+//go:linkname syscall_loadlibrary syscall.loadlibrary
+func syscall_loadlibrary(filename *uint16) (handle Handle, err Errno)
+
+//go:linkname syscall_getprocaddress syscall.getprocaddress
+func syscall_getprocaddress(handle Handle, procname *uint8) (proc uintptr, err Errno)
+
+// DLLError describes reasons for DLL load failures.
+type DLLError struct {
+	Err     error
+	ObjName string
+	Msg     string
+}
+
+func (e *DLLError) Error() string { return e.Msg }
+
+// A DLL implements access to a single DLL.
+type DLL struct {
+	Name   string
+	Handle Handle
+}
+
+// LoadDLL loads DLL file into memory.
+//
+// Warning: using LoadDLL without an absolute path name is subject to
+// DLL preloading attacks. To safely load a system DLL, use LazyDLL
+// with System set to true, or use LoadLibraryEx directly.
+func LoadDLL(name string) (dll *DLL, err error) {
+	namep, err := UTF16PtrFromString(name)
+	if err != nil {
+		return nil, err
+	}
+	h, e := syscall_loadlibrary(namep)
+	if e != 0 {
+		return nil, &DLLError{
+			Err:     e,
+			ObjName: name,
+			Msg:     "Failed to load " + name + ": " + e.Error(),
+		}
+	}
+	d := &DLL{
+		Name:   name,
+		Handle: h,
+	}
+	return d, nil
+}
+
+// MustLoadDLL is like LoadDLL but panics if load operation failes.
+func MustLoadDLL(name string) *DLL {
+	d, e := LoadDLL(name)
+	if e != nil {
+		panic(e)
+	}
+	return d
+}
+
+// FindProc searches DLL d for procedure named name and returns *Proc
+// if found. It returns an error if search fails.
+func (d *DLL) FindProc(name string) (proc *Proc, err error) {
+	namep, err := BytePtrFromString(name)
+	if err != nil {
+		return nil, err
+	}
+	a, e := syscall_getprocaddress(d.Handle, namep)
+	if e != 0 {
+		return nil, &DLLError{
+			Err:     e,
+			ObjName: name,
+			Msg:     "Failed to find " + name + " procedure in " + d.Name + ": " + e.Error(),
+		}
+	}
+	p := &Proc{
+		Dll:  d,
+		Name: name,
+		addr: a,
+	}
+	return p, nil
+}
+
+// MustFindProc is like FindProc but panics if search fails.
+func (d *DLL) MustFindProc(name string) *Proc {
+	p, e := d.FindProc(name)
+	if e != nil {
+		panic(e)
+	}
+	return p
+}
+
+// FindProcByOrdinal searches DLL d for procedure by ordinal and returns *Proc
+// if found. It returns an error if search fails.
+func (d *DLL) FindProcByOrdinal(ordinal uintptr) (proc *Proc, err error) {
+	a, e := GetProcAddressByOrdinal(d.Handle, ordinal)
+	name := "#" + itoa(int(ordinal))
+	if e != nil {
+		return nil, &DLLError{
+			Err:     e,
+			ObjName: name,
+			Msg:     "Failed to find " + name + " procedure in " + d.Name + ": " + e.Error(),
+		}
+	}
+	p := &Proc{
+		Dll:  d,
+		Name: name,
+		addr: a,
+	}
+	return p, nil
+}
+
+// MustFindProcByOrdinal is like FindProcByOrdinal but panics if search fails.
+func (d *DLL) MustFindProcByOrdinal(ordinal uintptr) *Proc {
+	p, e := d.FindProcByOrdinal(ordinal)
+	if e != nil {
+		panic(e)
+	}
+	return p
+}
+
+// Release unloads DLL d from memory.
+func (d *DLL) Release() (err error) {
+	return FreeLibrary(d.Handle)
+}
+
+// A Proc implements access to a procedure inside a DLL.
+type Proc struct {
+	Dll  *DLL
+	Name string
+	addr uintptr
+}
+
+// Addr returns the address of the procedure represented by p.
+// The return value can be passed to Syscall to run the procedure.
+func (p *Proc) Addr() uintptr {
+	return p.addr
+}
+
+//go:uintptrescapes
+
+// Call executes procedure p with arguments a. It will panic, if more than 15 arguments
+// are supplied.
+//
+// The returned error is always non-nil, constructed from the result of GetLastError.
+// Callers must inspect the primary return value to decide whether an error occurred
+// (according to the semantics of the specific function being called) before consulting
+// the error. The error will be guaranteed to contain windows.Errno.
+func (p *Proc) Call(a ...uintptr) (r1, r2 uintptr, lastErr error) {
+	switch len(a) {
+	case 0:
+		return syscall.Syscall(p.Addr(), uintptr(len(a)), 0, 0, 0)
+	case 1:
+		return syscall.Syscall(p.Addr(), uintptr(len(a)), a[0], 0, 0)
+	case 2:
+		return syscall.Syscall(p.Addr(), uintptr(len(a)), a[0], a[1], 0)
+	case 3:
+		return syscall.Syscall(p.Addr(), uintptr(len(a)), a[0], a[1], a[2])
+	case 4:
+		return syscall.Syscall6(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], 0, 0)
+	case 5:
+		return syscall.Syscall6(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], 0)
+	case 6:
+		return syscall.Syscall6(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5])
+	case 7:
+		return syscall.Syscall9(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], 0, 0)
+	case 8:
+		return syscall.Syscall9(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], 0)
+	case 9:
+		return syscall.Syscall9(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8])
+	case 10:
+		return syscall.Syscall12(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], 0, 0)
+	case 11:
+		return syscall.Syscall12(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], 0)
+	case 12:
+		return syscall.Syscall12(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], a[11])
+	case 13:
+		return syscall.Syscall15(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], a[11], a[12], 0, 0)
+	case 14:
+		return syscall.Syscall15(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], a[11], a[12], a[13], 0)
+	case 15:
+		return syscall.Syscall15(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], a[11], a[12], a[13], a[14])
+	default:
+		panic("Call " + p.Name + " with too many arguments " + itoa(len(a)) + ".")
+	}
+}
+
+// A LazyDLL implements access to a single DLL.
+// It will delay the load of the DLL until the first
+// call to its Handle method or to one of its
+// LazyProc's Addr method.
+type LazyDLL struct {
+	Name string
+
+	// System determines whether the DLL must be loaded from the
+	// Windows System directory, bypassing the normal DLL search
+	// path.
+	System bool
+
+	mu  sync.Mutex
+	dll *DLL // non nil once DLL is loaded
+}
+
+// Load loads DLL file d.Name into memory. It returns an error if fails.
+// Load will not try to load DLL, if it is already loaded into memory.
+func (d *LazyDLL) Load() error {
+	// Non-racy version of:
+	// if d.dll != nil {
+	if atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&d.dll))) != nil {
+		return nil
+	}
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	if d.dll != nil {
+		return nil
+	}
+
+	// kernel32.dll is special, since it's where LoadLibraryEx comes from.
+	// The kernel already special-cases its name, so it's always
+	// loaded from system32.
+	var dll *DLL
+	var err error
+	if d.Name == "kernel32.dll" {
+		dll, err = LoadDLL(d.Name)
+	} else {
+		dll, err = loadLibraryEx(d.Name, d.System)
+	}
+	if err != nil {
+		return err
+	}
+
+	// Non-racy version of:
+	// d.dll = dll
+	atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(&d.dll)), unsafe.Pointer(dll))
+	return nil
+}
+
+// mustLoad is like Load but panics if search fails.
+func (d *LazyDLL) mustLoad() {
+	e := d.Load()
+	if e != nil {
+		panic(e)
+	}
+}
+
+// Handle returns d's module handle.
+func (d *LazyDLL) Handle() uintptr {
+	d.mustLoad()
+	return uintptr(d.dll.Handle)
+}
+
+// NewProc returns a LazyProc for accessing the named procedure in the DLL d.
+func (d *LazyDLL) NewProc(name string) *LazyProc {
+	return &LazyProc{l: d, Name: name}
+}
+
+// NewLazyDLL creates new LazyDLL associated with DLL file.
+func NewLazyDLL(name string) *LazyDLL {
+	return &LazyDLL{Name: name}
+}
+
+// NewLazySystemDLL is like NewLazyDLL, but will only
+// search Windows System directory for the DLL if name is
+// a base name (like "advapi32.dll").
+func NewLazySystemDLL(name string) *LazyDLL {
+	return &LazyDLL{Name: name, System: true}
+}
+
+// A LazyProc implements access to a procedure inside a LazyDLL.
+// It delays the lookup until the Addr method is called.
+type LazyProc struct {
+	Name string
+
+	mu   sync.Mutex
+	l    *LazyDLL
+	proc *Proc
+}
+
+// Find searches DLL for procedure named p.Name. It returns
+// an error if search fails. Find will not search procedure,
+// if it is already found and loaded into memory.
+func (p *LazyProc) Find() error {
+	// Non-racy version of:
+	// if p.proc == nil {
+	if atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&p.proc))) == nil {
+		p.mu.Lock()
+		defer p.mu.Unlock()
+		if p.proc == nil {
+			e := p.l.Load()
+			if e != nil {
+				return e
+			}
+			proc, e := p.l.dll.FindProc(p.Name)
+			if e != nil {
+				return e
+			}
+			// Non-racy version of:
+			// p.proc = proc
+			atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(&p.proc)), unsafe.Pointer(proc))
+		}
+	}
+	return nil
+}
+
+// mustFind is like Find but panics if search fails.
+func (p *LazyProc) mustFind() {
+	e := p.Find()
+	if e != nil {
+		panic(e)
+	}
+}
+
+// Addr returns the address of the procedure represented by p.
+// The return value can be passed to Syscall to run the procedure.
+// It will panic if the procedure cannot be found.
+func (p *LazyProc) Addr() uintptr {
+	p.mustFind()
+	return p.proc.Addr()
+}
+
+//go:uintptrescapes
+
+// Call executes procedure p with arguments a. It will panic, if more than 15 arguments
+// are supplied. It will also panic if the procedure cannot be found.
+//
+// The returned error is always non-nil, constructed from the result of GetLastError.
+// Callers must inspect the primary return value to decide whether an error occurred
+// (according to the semantics of the specific function being called) before consulting
+// the error. The error will be guaranteed to contain windows.Errno.
+func (p *LazyProc) Call(a ...uintptr) (r1, r2 uintptr, lastErr error) {
+	p.mustFind()
+	return p.proc.Call(a...)
+}
+
+var canDoSearchSystem32Once struct {
+	sync.Once
+	v bool
+}
+
+func initCanDoSearchSystem32() {
+	// https://msdn.microsoft.com/en-us/library/ms684179(v=vs.85).aspx says:
+	// "Windows 7, Windows Server 2008 R2, Windows Vista, and Windows
+	// Server 2008: The LOAD_LIBRARY_SEARCH_* flags are available on
+	// systems that have KB2533623 installed. To determine whether the
+	// flags are available, use GetProcAddress to get the address of the
+	// AddDllDirectory, RemoveDllDirectory, or SetDefaultDllDirectories
+	// function. If GetProcAddress succeeds, the LOAD_LIBRARY_SEARCH_*
+	// flags can be used with LoadLibraryEx."
+	canDoSearchSystem32Once.v = (modkernel32.NewProc("AddDllDirectory").Find() == nil)
+}
+
+func canDoSearchSystem32() bool {
+	canDoSearchSystem32Once.Do(initCanDoSearchSystem32)
+	return canDoSearchSystem32Once.v
+}
+
+func isBaseName(name string) bool {
+	for _, c := range name {
+		if c == ':' || c == '/' || c == '\\' {
+			return false
+		}
+	}
+	return true
+}
+
+// loadLibraryEx wraps the Windows LoadLibraryEx function.
+//
+// See https://msdn.microsoft.com/en-us/library/windows/desktop/ms684179(v=vs.85).aspx
+//
+// If name is not an absolute path, LoadLibraryEx searches for the DLL
+// in a variety of automatic locations unless constrained by flags.
+// See: https://msdn.microsoft.com/en-us/library/ff919712%28VS.85%29.aspx
+func loadLibraryEx(name string, system bool) (*DLL, error) {
+	loadDLL := name
+	var flags uintptr
+	if system {
+		if canDoSearchSystem32() {
+			const LOAD_LIBRARY_SEARCH_SYSTEM32 = 0x00000800
+			flags = LOAD_LIBRARY_SEARCH_SYSTEM32
+		} else if isBaseName(name) {
+			// WindowsXP or unpatched Windows machine
+			// trying to load "foo.dll" out of the system
+			// folder, but LoadLibraryEx doesn't support
+			// that yet on their system, so emulate it.
+			systemdir, err := GetSystemDirectory()
+			if err != nil {
+				return nil, err
+			}
+			loadDLL = systemdir + "\\" + name
+		}
+	}
+	h, err := LoadLibraryEx(loadDLL, 0, flags)
+	if err != nil {
+		return nil, err
+	}
+	return &DLL{Name: name, Handle: h}, nil
+}
+
+type errString string
+
+func (s errString) Error() string { return string(s) }