code: func (b *builder) buildFuncDecl(pkg *Package, decl *ast.FuncDecl) {
  	id := decl.Name
  	if isBlankIdent(id) {
  		return // discard
  	}
  	fn := pkg.values[pkg.info.Defs[id]].(*Function)
  	if decl.Recv == nil && id.Name == "init" {
  		var v Call
  		v.Call.Value = fn
  		v.setType(types.NewTuple())
  		pkg.init.emit(&v)
  	}
  	b.buildFunction(fn)
  }
docs: // buildFuncDecl builds SSA code for the function or method declared
  // by decl in package pkg.
  //