Make kAsciiDataHintTag have correct semantics for all both 1 and 2 byte string types.

src/objects.h

 // 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 512 matching lines @@
 const uint32_t kShortcutTypeMask =
     kIsNotStringMask |
     kIsSymbolMask |
     kStringRepresentationMask;
 const uint32_t kShortcutTypeTag = kConsStringTag;
 
 
 enum InstanceType {
   // String types.
   SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kSeqStringTag,
-  ASCII_SYMBOL_TYPE = kOneByteStringTag | kSymbolTag | kSeqStringTag,
+  ASCII_SYMBOL_TYPE = kOneByteStringTag | kAsciiDataHintTag | kSymbolTag |
+                      kSeqStringTag,
   CONS_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kConsStringTag,
-  CONS_ASCII_SYMBOL_TYPE = kOneByteStringTag | kSymbolTag | kConsStringTag,
+  CONS_ASCII_SYMBOL_TYPE = kOneByteStringTag | kAsciiDataHintTag | kSymbolTag |
+                           kConsStringTag,
   SHORT_EXTERNAL_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag |
                                kExternalStringTag | kShortExternalStringTag,
   SHORT_EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE =
       kTwoByteStringTag | kSymbolTag | kExternalStringTag |
       kAsciiDataHintTag | kShortExternalStringTag,
-  SHORT_EXTERNAL_ASCII_SYMBOL_TYPE = kOneByteStringTag | kExternalStringTag |
-                                     kSymbolTag | kShortExternalStringTag,
+  SHORT_EXTERNAL_ASCII_SYMBOL_TYPE = kOneByteStringTag | kAsciiDataHintTag |
+                                     kExternalStringTag | kSymbolTag |
+                                     kShortExternalStringTag,
   EXTERNAL_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kExternalStringTag,
   EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE =
       kTwoByteStringTag | kSymbolTag | kExternalStringTag | kAsciiDataHintTag,
   EXTERNAL_ASCII_SYMBOL_TYPE =
-      kOneByteStringTag | kSymbolTag | kExternalStringTag,
+      kOneByteStringTag | kAsciiDataHintTag | kSymbolTag | kExternalStringTag,
   STRING_TYPE = kTwoByteStringTag | kSeqStringTag,
-  ASCII_STRING_TYPE = kOneByteStringTag | kSeqStringTag,
+  ASCII_STRING_TYPE = kOneByteStringTag | kAsciiDataHintTag | kSeqStringTag,
   CONS_STRING_TYPE = kTwoByteStringTag | kConsStringTag,
-  CONS_ASCII_STRING_TYPE = kOneByteStringTag | kConsStringTag,
+  CONS_ASCII_STRING_TYPE =
+      kOneByteStringTag | kAsciiDataHintTag | kConsStringTag,
   SLICED_STRING_TYPE = kTwoByteStringTag | kSlicedStringTag,
-  SLICED_ASCII_STRING_TYPE = kOneByteStringTag | kSlicedStringTag,
+  SLICED_ASCII_STRING_TYPE =
+      kOneByteStringTag | kAsciiDataHintTag | kSlicedStringTag,
   SHORT_EXTERNAL_STRING_TYPE =
       kTwoByteStringTag | kExternalStringTag | kShortExternalStringTag,
   SHORT_EXTERNAL_STRING_WITH_ASCII_DATA_TYPE =
       kTwoByteStringTag | kExternalStringTag |
       kAsciiDataHintTag | kShortExternalStringTag,
   SHORT_EXTERNAL_ASCII_STRING_TYPE =
-      kOneByteStringTag | kExternalStringTag | kShortExternalStringTag,
+      kOneByteStringTag | kAsciiDataHintTag |
+      kExternalStringTag | kShortExternalStringTag,
   EXTERNAL_STRING_TYPE = kTwoByteStringTag | kExternalStringTag,
   EXTERNAL_STRING_WITH_ASCII_DATA_TYPE =
       kTwoByteStringTag | kExternalStringTag | kAsciiDataHintTag,
   // LAST_STRING_TYPE
-  EXTERNAL_ASCII_STRING_TYPE = kOneByteStringTag | kExternalStringTag,
+  EXTERNAL_ASCII_STRING_TYPE =
+      kOneByteStringTag | kAsciiDataHintTag | kExternalStringTag,
   PRIVATE_EXTERNAL_ASCII_STRING_TYPE = EXTERNAL_ASCII_STRING_TYPE,
 
   // Objects allocated in their own spaces (never in new space).
   MAP_TYPE = kNotStringTag,  // FIRST_NONSTRING_TYPE
   CODE_TYPE,
   ODDBALL_TYPE,
   JS_GLOBAL_PROPERTY_CELL_TYPE,
 
   // "Data", objects that cannot contain non-map-word pointers to heap
   // objects.
@@ skipping 8464 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_