Crankshaft: Move LEnvironment and LPointerMap classes to platform-independent lithium.h.  Move WriteTranslation method from LEnvironment class to LCodeGen class.
Review URL: http://codereview.chromium.org/6142011

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6276 ce2b1a6d-e550-0410-aec6-3dcde31c8c00