Fix bogus uses of preparser API

* src/api.cc (ScriptData::PreCompile): Fix bogus use of bogus value for
  preparsing flags by removing those arguments, which were always zero.

* src/parser.h
* src/parser.cc (ParserApi::PreParse): Remove extension and flags
  arguments, both of which were either always 0 or incorrectly used.

* test/cctest/test-parsing.cc (RegressChromium62639, Regress928): Fix
  more bogus uses of preparser api.

BUG=

Review URL: https://codereview.chromium.org/13496008
Patch from Andy Wingo <wingo@igalia.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14140 ce2b1a6d-e550-0410-aec6-3dcde31c8c00