Create stand-alone json parser (including scanner).

src/objects.h

Index: src/objects.h
===================================================================
--- src/objects.h	(revision 7898)
+++ src/objects.h	(working copy)
@@ -2428,6 +2428,8 @@
   static const int kEntrySize = 1;
 };
 
+class SeqAsciiString;
+
 // SymbolTable.
 //
 // No special elements in the prefix and the element size is 1
@@ -2441,6 +2443,11 @@
   MUST_USE_RESULT MaybeObject* LookupSymbol(Vector<const char> str, Object** s);
   MUST_USE_RESULT MaybeObject* LookupAsciiSymbol(Vector<const char> str,
                                                  Object** s);
+  MUST_USE_RESULT MaybeObject* LookupSubStringAsciiSymbol(
+      Handle<SeqAsciiString> str,
+      int from,
+      int length,
+      Object** s);
   MUST_USE_RESULT MaybeObject* LookupTwoByteSymbol(Vector<const uc16> str,
                                                    Object** s);
   MUST_USE_RESULT MaybeObject* LookupString(String* key, Object** s);