golang timeasm 代码
文件路径：/src/runtime/timeasm.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.
/ Declarations for operating systems implementing time.now directly in assembly.
/go:build !faketime && (windows || (linux && amd64))
package runtime
import _ "unsafe"
/go:linkname time_now time.now
func time_now() (sec int64, nsec int32, mono int64)