A small collection of cleanup in the parser and AST.

A small collection of cleanup in the parser and AST.

* Remove a couple of unused fields from the FunctionLiteral, ensure that all
  the bools are packed.
* Rename SaveScope and LexicalScope in the parser.
* Use an enum to generate the numbers 0..N and the dependent count, rather
  than static const ints.  This is simpler to extend (coming in a future
  change).

R=danno@chromium.org,keuchel@chromium.org
BUG=
TEST=

Review URL: http://codereview.chromium.org/8505012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9933 ce2b1a6d-e550-0410-aec6-3dcde31c8c00