X87: Optimize the typeof operator.

src/x87/full-codegen-x87.cc

Index: src/x87/full-codegen-x87.cc
diff --git a/src/x87/full-codegen-x87.cc b/src/x87/full-codegen-x87.cc
index 3dbb6d41b128b27ddce603a58aff3e7c49f83d38..f1abd5befe21281f388a270770db9ea631466c92 100644
--- a/src/x87/full-codegen-x87.cc
+++ b/src/x87/full-codegen-x87.cc
@@ -4713,10 +4713,13 @@ void FullCodeGenerator::VisitUnaryOperation(UnaryOperation* expr) {
 
     case Token::TYPEOF: {
       Comment cmnt(masm_, "[ UnaryOperation (TYPEOF)");
-      { StackValueContext context(this);
+      {
+        AccumulatorValueContext context(this);
         VisitForTypeofValue(expr->expression());
       }
-      __ CallRuntime(Runtime::kTypeof, 1);
+      __ mov(ebx, eax);
+      TypeofStub typeof_stub(isolate());
+      __ CallStub(&typeof_stub);
       context()->Plug(eax);
       break;
     }