Avoid collecting symbol info for one-off preparsing.

src/parser.h

 // Copyright 2006-2008 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 194 matching lines @@
 
 // The parser: Takes a script and and context information, and builds a
 // FunctionLiteral AST node. Returns NULL and deallocates any allocated
 // AST nodes if parsing failed.
 FunctionLiteral* MakeAST(bool compile_in_global_context,
                          Handle<Script> script,
                          v8::Extension* extension,
                          ScriptDataImpl* pre_data,
                          bool is_json = false);
 
-
+// Generic preparser generating full preparse data.
 ScriptDataImpl* PreParse(Handle<String> source,
                          unibrow::CharacterStream* stream,
                          v8::Extension* extension);
 
+// Preparser that only does preprocessing that makes sense if only used
+// immediately after.
+ScriptDataImpl* PartialPreParse(Handle<String> source,
+                                unibrow::CharacterStream* stream,
+                                v8::Extension* extension);
+
 
 bool ParseRegExp(FlatStringReader* input,
                  bool multiline,
                  RegExpCompileData* result);
 
 
 // Support for doing lazy compilation. The script is the script containing full
 // source of the script where the function is declared. The start_position and
 // end_position specifies the part of the script source which has the source
 // for the function declaration in the form:
@@ skipping 36 matching lines @@
   static const int kTypeSlot = 0;
   static const int kElementsSlot = 1;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(CompileTimeValue);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_PARSER_H_