Correct bug with left shift on X64 platform from change 4571 (http://code.goo...

test/mjsunit/smi-ops.js

Index: test/mjsunit/smi-ops.js
===================================================================
--- test/mjsunit/smi-ops.js	(revision 4596)
+++ test/mjsunit/smi-ops.js	(working copy)
@@ -678,3 +678,10 @@
 
 assertEquals(4589934592, LogicalShiftRightByMultipleOf32(-2000000000));
 assertEquals(4589934592, LogicalShiftRightByMultipleOf32(-2000000000));
+
+// Verify that the shift amount is reduced modulo 32, not modulo 64.
+function LeftShiftThreeBy(x) {return 3 << x;}
+assertEquals(24, LeftShiftThreeBy(3));
+assertEquals(24, LeftShiftThreeBy(35));
+assertEquals(24, LeftShiftThreeBy(67));
+assertEquals(24, LeftShiftThreeBy(-29));