[project] change syscall to /x/sys/unix|windows

Changes most references of syscall to golang.org/x/sys/
Ones aren't changes include, Errno, Signal and SysProcAttr
as they haven't been implemented in /x/sys/.

Signed-off-by: Christopher Jones <tophj@linux.vnet.ibm.com>

[s390x] switch utsname from unsigned to signed

per 33267e036f
char in s390x in the /x/sys/unix package is now signed, so
change the buildtags

Signed-off-by: Christopher Jones <tophj@linux.vnet.ibm.com>

pkg/platform/architecture_linux.go

@@ -3,13 +3,13 @@
 package platform
 
 import (
-	"syscall"
+	"golang.org/x/sys/unix"
 )
 
 // runtimeArchitecture gets the name of the current architecture (x86, x86_64, …)
 func runtimeArchitecture() (string, error) {
-	utsname := &syscall.Utsname{}
-	if err := syscall.Uname(utsname); err != nil {
+	utsname := &unix.Utsname{}
+	if err := unix.Uname(utsname); err != nil {
 		return "", err
 	}
 	return charsToString(utsname.Machine), nil

pkg/platform/utsname_int8.go

@@ -1,5 +1,5 @@
-// +build linux,386 linux,amd64 linux,arm64
-// see golang's sources src/syscall/ztypes_linux_*.go that use int8
+// +build linux,386 linux,amd64 linux,arm64 s390x
+// see golang's sources golang.org/x/sys/unix/ztypes_linux_*.go that use int8
 
 package platform
 

pkg/platform/utsname_int8_test.go

@@ -1,4 +1,4 @@
-// +build linux,386 linux,amd64 linux,arm64
+// +build linux,386 linux,amd64 linux,arm64 s390x
 
 package platform
 

pkg/platform/utsname_uint8.go

@@ -1,5 +1,5 @@
-// +build linux,arm linux,ppc64 linux,ppc64le s390x
-// see golang's sources src/syscall/ztypes_linux_*.go that use uint8
+// +build linux,arm linux,ppc64 linux,ppc64le
+// see golang's sources golang.org/x/sys/unix/ztypes_linux_*.go that use uint8
 
 package platform
 

pkg/platform/utsname_uint8_test.go

@@ -1,4 +1,4 @@
-// +build linux,arm linux,ppc64 linux,ppc64le s390x
+// +build linux,arm linux,ppc64 linux,ppc64le
 
 package platform