[turbofan] Fix CheckedInt32Mod lowering for -0 case with negative left hand side.

test/mjsunit/regress/regress-5286.js

Index: test/mjsunit/regress/regress-5286.js
diff --git a/test/mjsunit/regress/regress-5286.js b/test/mjsunit/regress/regress-5286.js
new file mode 100644
index 0000000000000000000000000000000000000000..210d986a66fcc491c41f4c597f7623d13c0aac7d
--- /dev/null
+++ b/test/mjsunit/regress/regress-5286.js
@@ -0,0 +1,41 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+(function() {
+  function foo(x, y) { return x % y; }
+
+  assertEquals(0, foo(2, 2));
+  assertEquals(0, foo(4, 4));
+  %OptimizeFunctionOnNextCall(foo);
+  assertEquals(-0, foo(-8, 8));
+})();
+
+(function() {
+  function foo(x, y) { return x % y; }
+
+  assertEquals(0, foo(1, 1));
+  assertEquals(0, foo(2, 2));
+  %OptimizeFunctionOnNextCall(foo);
+  assertEquals(-0, foo(-3, 3));
+})();
+
+(function() {
+  function foo(x, y) { return x % y; }
+
+  assertEquals(0, foo(1, 1));
+  assertEquals(0, foo(2, 2));
+  %OptimizeFunctionOnNextCall(foo);
+  assertEquals(-0, foo(-2147483648, -1));
+})();
+
+(function() {
+  function foo(x, y) { return x % y; }
+
+  assertEquals(0, foo(1, 1));
+  assertEquals(0, foo(2, 2));
+  %OptimizeFunctionOnNextCall(foo);
+  assertEquals(-0, foo(-2147483648, -2147483648));
+})();