[Interpreter] Optimize equality check with null/undefined with a check on the map.

test/cctest/test-serialize.cc

 // Copyright 2007-2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1057 matching lines @@
 
   v8::HandleScope scope(CcTest::isolate());
 
   // The serializer only tests the shared code, which is always the unoptimized
   // code. Don't even bother generating optimized code to avoid timeouts.
   FLAG_always_opt = false;
 
   Vector<const uint8_t> source =
       ConstructSource(STATIC_CHAR_VECTOR("var j=1; if (j == 0) {"),
                       STATIC_CHAR_VECTOR("for (let i of Object.prototype);"),
-                      STATIC_CHAR_VECTOR("} j=7; j"), 1000);
+                      STATIC_CHAR_VECTOR("} j=7; j"), 1050);
   Handle<String> source_str =
       isolate->factory()->NewStringFromOneByte(source).ToHandleChecked();
 
   Handle<JSObject> global(isolate->context()->global_object());
   ScriptData* cache = NULL;
 
   Handle<SharedFunctionInfo> orig =
       CompileScript(isolate, source_str, Handle<String>(), &cache,
                     v8::ScriptCompiler::kProduceCodeCache);
 
@@ skipping 1212 matching lines @@
   }
   delete[] blob.data;
 }
 
 TEST(SerializationMemoryStats) {
   FLAG_profile_deserialization = true;
   FLAG_always_opt = false;
   v8::StartupData blob = v8::V8::CreateSnapshotDataBlob();
   delete[] blob.data;
 }