Remove much of the register allocation overhead from ARM. When...

Remove much of the register allocation overhead from ARM.  When
registers are required for calls, explicitly construct a Result with
the needed register rather than allocating it.  For returns from
calls, let the return value in r0 be implicit rather than explicitly
allocated.


Committed: http://code.google.com/p/v8/source/detail?r=2659

[Erik Corry, 2009-08-11 11:44:16]

LGTM