Some cleanup of the toplevel code generator:

Some cleanup of the toplevel code generator:

* Rename the operation of filling a context with a value.  Formerly it
  was 'Move', now it's 'Apply' so as to avoid confusion with various
  other Moves (eg, in the toplevel codegen, in the macro assemblers).

* Use the abstraction Drop rather than math on the stack pointer.

* Add a predicate on AST expression nodes to abstract a repeated test
  whether we should us a regular (named) IC or a keyed IC.

Review URL: http://codereview.chromium.org/546006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3580 ce2b1a6d-e550-0410-aec6-3dcde31c8c00