golang fcntl_libc 代码
文件路径：/src/internal/poll/fcntl_libc.go
/ Copyright 2019 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 aix || darwin || solaris
package poll
import _ "unsafe" / for go:linkname
/ Implemented in the syscall package.
/
/go:linkname fcntl syscall.fcntl
func fcntl(fd int, cmd int, arg int) (int, error)