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

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index cab8d377b0a1291076ffafa12aa49d38aa7e227c..63c4b042f25482bc2ec7b071be60a78f2051307d 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -1125,7 +1125,7 @@ void LCodeGen::DoMulI(LMulI* instr) {
     __ testl(left, 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 (right->IsStackSlot()) {