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

Change-Id: I8d5a554409115b29318089671ca4e1ab3fa98810
diff --git a/vendor/golang.org/x/sys/unix/syscall_darwin.1_13.go b/vendor/golang.org/x/sys/unix/syscall_darwin.1_13.go
index dc0befe..1596426 100644
--- a/vendor/golang.org/x/sys/unix/syscall_darwin.1_13.go
+++ b/vendor/golang.org/x/sys/unix/syscall_darwin.1_13.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build darwin && go1.13
 // +build darwin,go1.13
 
 package unix
@@ -16,7 +17,7 @@
 //sys	readdir_r(dir uintptr, entry *Dirent, result **Dirent) (res Errno)
 
 func fdopendir(fd int) (dir uintptr, err error) {
-	r0, _, e1 := syscall_syscallPtr(funcPC(libc_fdopendir_trampoline), uintptr(fd), 0, 0)
+	r0, _, e1 := syscall_syscallPtr(libc_fdopendir_trampoline_addr, uintptr(fd), 0, 0)
 	dir = uintptr(r0)
 	if e1 != 0 {
 		err = errnoErr(e1)
@@ -24,9 +25,8 @@
 	return
 }
 
-func libc_fdopendir_trampoline()
+var libc_fdopendir_trampoline_addr uintptr
 
-//go:linkname libc_fdopendir libc_fdopendir
 //go:cgo_import_dynamic libc_fdopendir fdopendir "/usr/lib/libSystem.B.dylib"
 
 func Getdirentries(fd int, buf []byte, basep *uintptr) (n int, err error) {