compiler: build separation runtime with clite

runtime/internal/clite/syscall/unix/at_sysnum_netbsd.go

@@ -0,0 +1,10 @@
+// Copyright 2018 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 unix
+
+const AT_REMOVEDIR = 0x800
+const AT_SYMLINK_NOFOLLOW = 0x200
+
+const UTIME_OMIT = (1 << 30) - 2