[stubs] Unify (and optimize) implementation of ToObject.

src/ia32/code-stubs-ia32.cc

Index: src/ia32/code-stubs-ia32.cc
diff --git a/src/ia32/code-stubs-ia32.cc b/src/ia32/code-stubs-ia32.cc
index 525edea8993191ca2be5c82da52695de085bd0c2..bf2630b94474f1f06ce0a63654f6a6fd13122ab6 100644
--- a/src/ia32/code-stubs-ia32.cc
+++ b/src/ia32/code-stubs-ia32.cc
@@ -2093,8 +2093,8 @@ static void EmitWrapCase(MacroAssembler* masm, int argc, Label* cont) {
   // Wrap the receiver and patch it back onto the stack.
   { FrameScope frame_scope(masm, StackFrame::INTERNAL);
     __ push(edi);
-    __ push(eax);
-    __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
+    ToObjectStub stub(masm->isolate());
+    __ CallStub(&stub);
     __ pop(edi);
   }
   __ mov(Operand(esp, (argc + 1) * kPointerSize), eax);