X87: [stubs] Introduce a dedicated FastNewObjectStub.

src/x87/macro-assembler-x87.cc

Index: src/x87/macro-assembler-x87.cc
diff --git a/src/x87/macro-assembler-x87.cc b/src/x87/macro-assembler-x87.cc
index 4f6f01d5d76a26bf52b219391026285d5e0926e7..0c459ebfd420f5208d8b4b7c05ef6a26d831a4c3 100644
--- a/src/x87/macro-assembler-x87.cc
+++ b/src/x87/macro-assembler-x87.cc
@@ -900,6 +900,17 @@ void MacroAssembler::AssertBoundFunction(Register object) {
   }
 }
 
+void MacroAssembler::AssertReceiver(Register object) {
+  if (emit_debug_code()) {
+    test(object, Immediate(kSmiTagMask));
+    Check(not_equal, kOperandIsASmiAndNotAReceiver);
+    Push(object);
+    STATIC_ASSERT(LAST_TYPE == LAST_JS_RECEIVER_TYPE);
+    CmpObjectType(object, FIRST_JS_RECEIVER_TYPE, object);
+    Pop(object);
+    Check(above_equal, kOperandIsNotAReceiver);
+  }
+}
 
 void MacroAssembler::AssertUndefinedOrAllocationSite(Register object) {
   if (emit_debug_code()) {