gRPC migration update

Change-Id: Icdd1a824948fa994cd36bd121c962f5ecf74e3cf
diff --git a/vendor/golang.org/x/sys/unix/syscall_darwin_libSystem.go b/vendor/golang.org/x/sys/unix/syscall_darwin_libSystem.go
index 4b4ae46..53c9664 100644
--- a/vendor/golang.org/x/sys/unix/syscall_darwin_libSystem.go
+++ b/vendor/golang.org/x/sys/unix/syscall_darwin_libSystem.go
@@ -2,11 +2,12 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build darwin && go1.12
 // +build darwin,go1.12
 
 package unix
 
-import "unsafe"
+import _ "unsafe"
 
 // Implemented in the runtime package (runtime/sys_darwin.go)
 func syscall_syscall(fn, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)
@@ -15,6 +16,7 @@
 func syscall_syscall9(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2 uintptr, err Errno) // 32-bit only
 func syscall_rawSyscall(fn, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)
 func syscall_rawSyscall6(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno)
+func syscall_syscallPtr(fn, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)
 
 //go:linkname syscall_syscall syscall.syscall
 //go:linkname syscall_syscall6 syscall.syscall6
@@ -22,10 +24,4 @@
 //go:linkname syscall_syscall9 syscall.syscall9
 //go:linkname syscall_rawSyscall syscall.rawSyscall
 //go:linkname syscall_rawSyscall6 syscall.rawSyscall6
-
-// Find the entry point for f. See comments in runtime/proc.go for the
-// function of the same name.
-//go:nosplit
-func funcPC(f func()) uintptr {
-	return **(**uintptr)(unsafe.Pointer(&f))
-}
+//go:linkname syscall_syscallPtr syscall.syscallPtr