Migrate some case conversion functions from JS to CPP builtins

src/builtins/builtins.h

 // Copyright 2011 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_BUILTINS_BUILTINS_H_
 #define V8_BUILTINS_BUILTINS_H_
 
 #include "src/base/flags.h"
 #include "src/globals.h"
 
@@ skipping 753 matching lines @@
   TFJ(StringPrototypeSplit, 2)                                                 \
   /* ES6 section B.2.3.1 String.prototype.substr ( start, length ) */          \
   TFJ(StringPrototypeSubstr, 2)                                                \
   /* ES6 section 21.1.3.19 String.prototype.substring ( start, end ) */        \
   TFJ(StringPrototypeSubstring, 2)                                             \
   /* ES6 section 21.1.3.20 */                                                  \
   /* String.prototype.startsWith ( searchString [ , position ] ) */            \
   CPP(StringPrototypeStartsWith)                                               \
   /* ES6 section 21.1.3.25 String.prototype.toString () */                     \
   TFJ(StringPrototypeToString, 0)                                              \
+  /* (obsolete) Unibrow string functions */                                    \
+  CPP(StringPrototypeToLocaleLowerCase)                                        \
+  CPP(StringPrototypeToLocaleUpperCase)                                        \
+  CPP(StringPrototypeToLowerCase)                                              \
+  CPP(StringPrototypeToUpperCase)                                              \
   /* ES #sec-string.prototype.tolocalelowercase */                             \
-  CPP(StringPrototypeToLocaleLowerCase)                                        \
+  /* CPP(StringPrototypeToLocaleLowerCaseI18N) */                              \
   /* ES #sec-string.prototype.tolocaleuppercase */                             \
-  CPP(StringPrototypeToLocaleUpperCase)                                        \
+  /* CPP(StringPrototypeToLocaleUpperCaseI18N) */                              \
   /* ES #sec-string.prototype.tolowercase */                                   \
-  CPP(StringPrototypeToLowerCase)                                              \
+  CPP(StringPrototypeToLowerCaseI18N)                                          \
   /* ES #sec-string.prototype.touppercase */                                   \
-  CPP(StringPrototypeToUpperCase)                                              \
+  CPP(StringPrototypeToUpperCaseI18N)                                          \
   CPP(StringPrototypeTrim)                                                     \
   CPP(StringPrototypeTrimLeft)                                                 \
   CPP(StringPrototypeTrimRight)                                                \
   /* ES6 section 21.1.3.28 String.prototype.valueOf () */                      \
   TFJ(StringPrototypeValueOf, 0)                                               \
   /* ES6 #sec-string.prototype-@@iterator */                                   \
   TFJ(StringPrototypeIterator, 0)                                              \
                                                                                \
   /* StringIterator */                                                         \
   TFJ(StringIteratorPrototypeNext, 0)                                          \
@@ skipping 202 matching lines @@
 
   friend class Isolate;
 
   DISALLOW_COPY_AND_ASSIGN(Builtins);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_BUILTINS_BUILTINS_H_