golang write_err 代码
文件路径：/src/runtime/write_err.go
/ Copyright 2009 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.
/go:build !android
package runtime
import "unsafe"
func writeErr(b []byte) {
write(2, unsafe.Pointer(&b[0]), int32(len(b)))
}