Add more tests to mul-exhaustive for constant left/right parameters.

test/mjsunit/negate-zero.js

Index: test/mjsunit/negate-zero.js
diff --git a/test/mjsunit/negate-zero.js b/test/mjsunit/negate-zero.js
index 31d460a2dea894be4a997cf8f7350f938e1e77d1..558be94c3d4f699e597e01cbe4e374597dda93d0 100644
--- a/test/mjsunit/negate-zero.js
+++ b/test/mjsunit/negate-zero.js
@@ -26,7 +26,7 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 function IsNegativeZero(x) {
-  assertEquals(0, x);
+  assertTrue(x == 0);  // Is 0 or -0.
   var y = 1 / x;
   assertFalse(isFinite(y));
   return y < 0;