Fix register clobbering in LoadIC for interceptors.

test/cctest/test-api.cc

 // Copyright 2012 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 16194 matching lines @@
   CHECK(result5->Equals(
       object_with_hidden->GetPrototype()->ToObject()->GetPrototype()));
 
   Local<Value> result6 = CompileRun("Object.getPrototypeOf(phidden)");
   CHECK(result6->Equals(Undefined()));
 
   context.Dispose();
 }
 
 
+THREADED_TEST(Regress125988) {
+  v8::HandleScope scope;
+  Handle<FunctionTemplate> intercept = FunctionTemplate::New();
+  AddInterceptor(intercept, EmptyInterceptorGetter, EmptyInterceptorSetter);
+  LocalContext env;
+  env->Global()->Set(v8_str("Intercept"), intercept->GetFunction());
+  CompileRun("var a = new Object();"
+             "var b = new Intercept();"
+             "var c = new Object();"
+             "c.__proto__ = b;"
+             "b.__proto__ = a;"
+             "a.x = 23;"
+             "for (var i = 0; i < 3; i++) c.x;");
+  ExpectBoolean("c.hasOwnProperty('x')", false);
+  ExpectInt32("c.x", 23);
+  CompileRun("a.y = 42;"
+             "for (var i = 0; i < 3; i++) c.x;");
+  ExpectBoolean("c.hasOwnProperty('x')", false);
+  ExpectInt32("c.x", 23);
+  ExpectBoolean("c.hasOwnProperty('y')", false);
+  ExpectInt32("c.y", 42);
+}
+
+
 static void TestReceiver(Local<Value> expected_result,
                          Local<Value> expected_receiver,
                          const char* code) {
   Local<Value> result = CompileRun(code);
   CHECK(result->IsObject());
   CHECK(expected_receiver->Equals(result->ToObject()->Get(1)));
   CHECK(expected_result->Equals(result->ToObject()->Get(0)));
 }
 
 
@@ skipping 337 matching lines @@
   v8::V8::SetFatalErrorHandler(CountingErrorCallback);
   v8::Utils::ReportApiFailure("StringEmpty()", "Kill V8");
   i::Isolate::Current()->TearDown();
   CHECK(!i::Internals::IsInitialized(isolate));
   CHECK_EQ(1, fatal_error_callback_counter);
   CHECK(v8::String::Empty().IsEmpty());
   CHECK_EQ(2, fatal_error_callback_counter);
   CHECK(v8::String::Empty(isolate).IsEmpty());
   CHECK_EQ(3, fatal_error_callback_counter);
 }