[VOL-4291] Rw-core updates for gRPC migration

Change-Id: I8d5a554409115b29318089671ca4e1ab3fa98810
diff --git a/vendor/golang.org/x/sys/unix/syscall.go b/vendor/golang.org/x/sys/unix/syscall.go
index fd4ee8e..649fa87 100644
--- a/vendor/golang.org/x/sys/unix/syscall.go
+++ b/vendor/golang.org/x/sys/unix/syscall.go
@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
+//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris || zos
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris zos
 
 // Package unix contains an interface to the low-level operating system
 // primitives. OS details vary depending on the underlying system, and
@@ -24,7 +25,13 @@
 // holds a value of type syscall.Errno.
 package unix // import "golang.org/x/sys/unix"
 
-import "strings"
+import (
+	"bytes"
+	"strings"
+	"unsafe"
+
+	"golang.org/x/sys/internal/unsafeheader"
+)
 
 // ByteSliceFromString returns a NUL-terminated slice of bytes
 // containing the text of s. If s contains a NUL byte at any
@@ -49,5 +56,40 @@
 	return &a[0], nil
 }
 
+// ByteSliceToString returns a string form of the text represented by the slice s, with a terminating NUL and any
+// bytes after the NUL removed.
+func ByteSliceToString(s []byte) string {
+	if i := bytes.IndexByte(s, 0); i != -1 {
+		s = s[:i]
+	}
+	return string(s)
+}
+
+// BytePtrToString takes a pointer to a sequence of text and returns the corresponding string.
+// If the pointer is nil, it returns the empty string. It assumes that the text sequence is terminated
+// at a zero byte; if the zero byte is not present, the program may crash.
+func BytePtrToString(p *byte) string {
+	if p == nil {
+		return ""
+	}
+	if *p == 0 {
+		return ""
+	}
+
+	// Find NUL terminator.
+	n := 0
+	for ptr := unsafe.Pointer(p); *(*byte)(ptr) != 0; n++ {
+		ptr = unsafe.Pointer(uintptr(ptr) + 1)
+	}
+
+	var s []byte
+	h := (*unsafeheader.Slice)(unsafe.Pointer(&s))
+	h.Data = unsafe.Pointer(p)
+	h.Len = n
+	h.Cap = n
+
+	return string(s)
+}
+
 // Single-word zero for use when we need a valid pointer to 0 bytes.
 var _zero uintptr