X87: Correctify instanceof and make it optimizable.

src/full-codegen/x87/full-codegen-x87.cc

Index: src/full-codegen/x87/full-codegen-x87.cc
diff --git a/src/full-codegen/x87/full-codegen-x87.cc b/src/full-codegen/x87/full-codegen-x87.cc
index db5e1f6d5f768124bf1f06987aa3b7f0550bc3cb..25b8171487f5a351b38836aa2d42fe832a6b4b6d 100644
--- a/src/full-codegen/x87/full-codegen-x87.cc
+++ b/src/full-codegen/x87/full-codegen-x87.cc
@@ -5023,13 +5023,13 @@ void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
       break;
 
     case Token::INSTANCEOF: {
-      VisitForStackValue(expr->right());
-      InstanceofStub stub(isolate(), InstanceofStub::kNoFlags);
+      VisitForAccumulatorValue(expr->right());
+      __ Pop(edx);
+      InstanceOfStub stub(isolate());
       __ CallStub(&stub);
-      PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-      __ test(eax, eax);
-      // The stub returns 0 for true.
-      Split(zero, if_true, if_false, fall_through);
+      PrepareForBailoutBeforeSplit(expr, false, NULL, NULL);
+      __ cmp(eax, isolate()->factory()->true_value());
+      Split(equal, if_true, if_false, fall_through);
       break;
     }