[builtins] Move StringIndexOf to a builtin.

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/handles.h"
 
@@ skipping 517 matching lines @@
   /* String */                                                                \
   ASM(StringConstructor)                                                      \
   ASM(StringConstructor_ConstructStub)                                        \
   CPP(StringFromCodePoint)                                                    \
   /* ES6 section 21.1.2.1 String.fromCharCode ( ...codeUnits ) */             \
   TFJ(StringFromCharCode, 2)                                                  \
   /* ES6 section 21.1.3.1 String.prototype.charAt ( pos ) */                  \
   TFJ(StringPrototypeCharAt, 2)                                               \
   /* ES6 section 21.1.3.2 String.prototype.charCodeAt ( pos ) */              \
   TFJ(StringPrototypeCharCodeAt, 2)                                           \
+  /* ES6 section 21.1.3.8 */                                                  \
+  /* String.prototype.indexOf ( searchString [ , position ] ) */              \
+  CPP(StringPrototypeIndexOf)                                                 \
   /* ES6 section 21.1.3.9 */                                                  \
   /* String.prototype.lastIndexOf ( searchString [ , position ] ) */          \
   CPP(StringPrototypeLastIndexOf)                                             \
   /* ES6 section 21.1.3.10 String.prototype.localeCompare ( that ) */         \
   CPP(StringPrototypeLocaleCompare)                                           \
   /* ES6 section 21.1.3.12 String.prototype.normalize ( [form] ) */           \
   CPP(StringPrototypeNormalize)                                               \
   /* ES6 section 21.1.3.25 String.prototype.toString () */                    \
   TFJ(StringPrototypeToString, 1)                                             \
   CPP(StringPrototypeTrim)                                                    \
@@ skipping 162 matching lines @@
 
   friend class Isolate;
 
   DISALLOW_COPY_AND_ASSIGN(Builtins);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_BUILTINS_BUILTINS_H_