golang iscgo 代码
文件路径：/src/runtime/cgo/iscgo.go
/ Copyright 2010 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.
/ The runtime package contains an uninitialized definition
/ for runtime·iscgo. Override it to tell the runtime we're here.
/ There are various function pointers that should be set too,
/ but those depend on dynamic linker magic to get initialized
/ correctly, and sometimes they break. This variable is a
/ backup: it depends only on old C style static linking rules.
package cgo
import _ "unsafe" / for go:linkname
/go:linkname _iscgo runtime.iscgo
var _iscgo bool = true