A few hot Date.prototype functions used to be implemented as
DateGetFoo calling GetFooFrom(this), and other callers of GetFooFrom
did repeated date value extraction.  In this change GetFooFrom
functions were inlined into the functions on the prototype and the
other callers switched to using date values directly.

Review URL: http://codereview.chromium.org/2841041

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5027 ce2b1a6d-e550-0410-aec6-3dcde31c8c00