Merge r5192 (Re-apply support for ES5's propertyname production)

TBR=lrn@chromium.org
Review URL: http://codereview.chromium.org/3061056

git-svn-id: http://v8.googlecode.com/svn/trunk@5193 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
diff --git a/src/token.h b/src/token.h
index 2a228d6..0d8960b 100644
--- a/src/token.h
+++ b/src/token.h
@@ -220,6 +220,10 @@
   }
 
   // Predicates
+  static bool IsKeyword(Value tok) {
+    return token_type[tok] == 'K';
+  }
+
   static bool IsAssignmentOp(Value tok) {
     return INIT_VAR <= tok && tok <= ASSIGN_MOD;
   }
@@ -263,6 +267,7 @@
   static const char* name_[NUM_TOKENS];
   static const char* string_[NUM_TOKENS];
   static int8_t precedence_[NUM_TOKENS];
+  static const char token_type[NUM_TOKENS];
 };
 
 } }  // namespace v8::internal