golang target 代码
文件路径：/src/cmd/compile/internal/typecheck/target.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:generate go run mkbuiltin.go
package typecheck
import "cmd/compile/internal/ir"
/ Target is the package being compiled.
var Target *ir.Package