Make VirtualFrame::CallStub on IA32 responsible for moving arguments...

Make VirtualFrame::CallStub on IA32 responsible for moving arguments
into the appropriate registers for the stub call.  Since stubs that
take arguments in registers do not (currently) take any arguments on
the stack, the unused generality has been removed (it's easy to put
back in later).

Committed: http://code.google.com/p/v8/source/detail?r=1629

[Kevin Millikin (Chromium), 2009-03-27 07:05:43]

This is the last part of the cleanup of the way we emit calls in the code
generator.  Only the load/store ICs made much of a performance difference.

We should now be in a better position to change the calling conventions without
having to change every call site in the code generator.

ARM still uses the old design.

[William Hesse, 2009-03-27 10:26:43]

LGTM.