cmd/compile: fix ICE with parenthesized builtin calls

CL 419456 starts using lookupObj to find types2.Object associated with
builtin functions. However, the new code does not un-parenthesized the
callee expression, causing an ICE because of nil obj returned.

Un-parenthesizing the callee expression fixes the problem.

Fixes #63436

Change-Id: Iebb4fbc08575e7d0b1dbd026c98e8f949ca16460
Reviewed-on: https://go-review.googlesource.com/c/go/+/533476
Auto-Submit: Cuong Manh Le <[email protected]>
Reviewed-by: Keith Randall <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Matthew Dempsky <[email protected]>
Reviewed-by: Keith Randall <[email protected]>

Author: cuonglm

src/cmd/compile/internal/noder/writer.go

@@ -1909,7 +1909,7 @@ func (w *writer) expr(expr syntax.Expr) {
 
 		var rtype types2.Type
 		if tv.IsBuiltin() {
-			switch obj, _ := lookupObj(w.p, expr.Fun); obj.Name() {
+			switch obj, _ := lookupObj(w.p, syntax.Unparen(expr.Fun)); obj.Name() {
 			case "make":
 				assert(len(expr.ArgList) >= 1)
 				assert(!expr.HasDots)

test/fixedbugs/issue63436.go

@@ -0,0 +1,9 @@
+// compile
+
+// Copyright 2023 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.
+
+package p
+
+var _ = (new)(int)