issue 789: keep test case

R=rsc
CC=golang-dev
https://golang.org/cl/1242045

test/fixedbugs/bug276.go

+// $G $D/$F.go && $L $F.$A && ./$A.out || echo BUG code should run
+
+// 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.
+
+// Test case for issue 789. The bug only appeared for GOARCH=386.
+
+package main
+
+func main() {
+	i := 0
+	x := 0
+
+	a := (x & 1) << uint(1-i)
+	
+	s := uint(1-i)
+	b := (x & 1) << s
+	
+	if a != b {
+		panic(0)
+	}
+}