Add parser support for generators.

src/token.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 156 matching lines @@
   /* Identifiers (not keywords or future reserved words). */            \
   T(IDENTIFIER, NULL, 0)                                                \
                                                                         \
   /* Future reserved words (ECMA-262, section 7.6.1.2). */              \
   T(FUTURE_RESERVED_WORD, NULL, 0)                                      \
   T(FUTURE_STRICT_RESERVED_WORD, NULL, 0)                               \
   K(CONST, "const", 0)                                                  \
   K(EXPORT, "export", 0)                                                \
   K(IMPORT, "import", 0)                                                \
   K(LET, "let", 0)                                                      \
+  K(YIELD, "yield", 0)                                                  \
                                                                         \
   /* Illegal token - not able to scan. */                               \
   T(ILLEGAL, "ILLEGAL", 0)                                              \
                                                                         \
   /* Scanner-internal use only. */                                      \
   T(WHITESPACE, NULL, 0)
 
 
 class Token {
  public:
@@ skipping 105 matching lines @@
  private:
   static const char* const name_[NUM_TOKENS];
   static const char* const string_[NUM_TOKENS];
   static const int8_t precedence_[NUM_TOKENS];
   static const char token_type[NUM_TOKENS];
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_TOKEN_H_