[string] Move String.p.toLowerCase to CSA

src/builtins/builtins-intl.cc

 // Copyright 2017 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_INTL_SUPPORT
 #error Internationalization is expected to be enabled.
 #endif  // V8_INTL_SUPPORT
 
 #include "src/builtins/builtins-utils.h"
 #include "src/builtins/builtins.h"
 #include "src/intl.h"
 #include "src/objects-inl.h"
 
 #include "unicode/normalizer2.h"
 
 namespace v8 {
 namespace internal {
 
-BUILTIN(StringPrototypeToLowerCaseIntl) {
-  HandleScope scope(isolate);
-  TO_THIS_STRING(string, "String.prototype.toLowerCase");
-  string = String::Flatten(string);
-  return ConvertCase(string, false, isolate);
-}
-
 BUILTIN(StringPrototypeToUpperCaseIntl) {
   HandleScope scope(isolate);
   TO_THIS_STRING(string, "String.prototype.toUpperCase");
   string = String::Flatten(string);
   return ConvertCase(string, true, isolate);
 }
 
 BUILTIN(StringPrototypeNormalizeIntl) {
   HandleScope handle_scope(isolate);
   TO_THIS_STRING(string, "String.prototype.normalize");
@@ skipping 63 matching lines @@
   }
 
   RETURN_RESULT_OR_FAILURE(
       isolate, isolate->factory()->NewStringFromTwoByte(Vector<const uint16_t>(
                    reinterpret_cast<const uint16_t*>(result.getBuffer()),
                    result.length())));
 }
 
 }  // namespace internal
 }  // namespace v8