build: separate compiler and libs

compiler/internal/lib/os/path_plan9.go

@@ -0,0 +1,19 @@
+// Copyright 2011 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 os
+
+const (
+	PathSeparator     = '/'    // OS-specific path separator
+	PathListSeparator = '\000' // OS-specific path list separator
+)
+
+// IsPathSeparator reports whether c is a directory separator character.
+func IsPathSeparator(c uint8) bool {
+	return PathSeparator == c
+}
+
+func fixRootDirectory(p string) string {
+	return p
+}