Avoid wrong imul deopt on ia32 and x64 (fixes v8 bug 2339).

src/ia32/lithium-codegen-ia32.cc

Index: src/ia32/lithium-codegen-ia32.cc
diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index 7d413b9f622ff4f66eb4b5e055ff2dfaeaff861d..da17e297637f01656e5f7708be1aebf376ff2bfb 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -1234,8 +1234,11 @@ void LCodeGen::DoMulI(LMulI* instr) {
     __ test(left, Operand(left));
     __ j(not_zero, &done, Label::kNear);
     if (right->IsConstantOperand()) {
-      if (ToInteger32(LConstantOperand::cast(right)) <= 0) {
+      if (ToInteger32(LConstantOperand::cast(right)) < 0) {
         DeoptimizeIf(no_condition, instr->environment());
+      } else if (ToInteger32(LConstantOperand::cast(right)) == 0) {
+        __ cmp(ToRegister(instr->temp()), Immediate(0));
+        DeoptimizeIf(less, instr->environment());
       }
     } else {
       // Test the non-zero operand for negative sign.