Revert of [runtime] Remove useless IN builtin.

src/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_H_
 #define V8_BUILTINS_H_
 
 namespace v8 {
 namespace internal {
 
@@ skipping 157 matching lines @@
   V(BIT_AND, 1)                            \
   V(BIT_AND_STRONG, 1)                     \
   V(BIT_XOR, 1)                            \
   V(BIT_XOR_STRONG, 1)                     \
   V(SHL, 1)                                \
   V(SHL_STRONG, 1)                         \
   V(SAR, 1)                                \
   V(SAR_STRONG, 1)                         \
   V(SHR, 1)                                \
   V(SHR_STRONG, 1)                         \
+  V(IN, 1)                                 \
   V(INSTANCE_OF, 1)                        \
   V(CALL_NON_FUNCTION, 0)                  \
   V(CALL_NON_FUNCTION_AS_CONSTRUCTOR, 0)   \
   V(CALL_FUNCTION_PROXY, 1)                \
   V(CALL_FUNCTION_PROXY_AS_CONSTRUCTOR, 1) \
   V(TO_NUMBER, 0)                          \
   V(TO_STRING, 0)                          \
   V(TO_NAME, 0)                            \
   V(STRING_ADD_LEFT, 1)                    \
   V(STRING_ADD_RIGHT, 1)                   \
@@ skipping 156 matching lines @@
 
   friend class BuiltinFunctionTable;
   friend class Isolate;
 
   DISALLOW_COPY_AND_ASSIGN(Builtins);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_BUILTINS_H_