code review 6845113: cmd/gc: Error out on division by constant zero.

test/fixedbugs/issue4264.go

+// errorcheck
+
+// Copyright 2013 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.
+
+// issue 4264: reject int division by const 0
+
+package main
+
+func main() {
+        var x int
+        var y float64
+        var z complex128
+
+        println(x/0) // ERROR "division by zero"
+        println(y/0)
+        println(z/0)
+}