golang bootstrap 代码
文件路径：/src/cmd/compile/internal/gc/bootstrap.go
/ Copyright 2017 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 !go1.8
/ +build !go1.8
package gc
import (
"cmd/compile/internal/base"
"runtime"
)
func startMutexProfiling() {
base.Fatalf("mutex profiling unavailable in version %v", runtime.Version())
}