Refactor scope and function state tracking in (Pre)Parser.

Notes:
- PreParser::Scope was a weird combination of Parser::FunctionState and
  Scope. Split it into two (PreParser::FunctionState and PreParser::Scope). This
  is necessary for unifying the Parser and the PreParser.
- Scopes take care of language mode and tracking "with".
- FunctionStates take care of counting material literal indexes, properties
  etc. and tracking generators.
- PreParser::Scope::InsideWith was a hack to make a FunctionState-like object
  take care of tracking "with". It's now the responsibility fo PreParser::Scope
  and Scope.
- PreParser::ScopeType is unnecessarly, there is already a ScopeType enum in
v8globals.h.
- Renamed scope stack variables so that they're consistent in Parser and PreParser.
- Parser::FunctionState and Parser::BlockState had an unnecessary dependency to
  the Parser; they only need a couple of things from Parser. Broke the
  dependency.

R=ulan@chromium.org
BUG=v8:3126
LOG=N

Review URL: https://codereview.chromium.org/148293011

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19319 ce2b1a6d-e550-0410-aec6-3dcde31c8c00