cmd/compile: fix ICE with new(<untyped expr>)

Fixes #75617

Change-Id: Iaee7d4556db54b9999f5ba8458e7c05c11ccfc36
Reviewed-on: https://go-review.googlesource.com/c/go/+/707075
Reviewed-by: Junyang Shao <shaojunyang@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Alan Donovan <adonovan@google.com>

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

@@ -2434,6 +2434,7 @@ func (r *reader) expr() (res ir.Node) {
 		if r.Bool() {
 			// new(expr) -> tmp := expr; &tmp
 			x := r.expr()
+			x = typecheck.DefaultLit(x, nil) // See TODO in exprConvert case.
 			var init ir.Nodes
 			addr := ir.NewAddrExpr(pos, r.tempCopy(pos, x, &init))
 			addr.SetInit(init)

test/newexpr.go

@@ -29,4 +29,11 @@ func main() {
 			panic("wrong value")
 		}
 	}
+	{
+		var i int
+		v := new(i > 0) // untyped expression, see issue #75617
+		if *v != false {
+			panic("wrong value")
+		}
+	}
 }