Use moveDoubleToInts in SpecializedThunkJIT::returnDouble for non-X86 JSVALUE32_64 ports.

https://bugs.webkit.org/show_bug.cgi?id=124936

Patch by Julien Brianceau <jbriance@cisco.com> on 2013-11-29
Reviewed by Zoltan Herczeg.

The moveDoubleToInts implementations in ARM, MIPS and SH4 macro assemblers do not clobber
src FPRegister and are likely to be more efficient than the current generic implementation
using the stack.

* jit/SpecializedThunkJIT.h:
(JSC::SpecializedThunkJIT::returnDouble):

Change-Id: Ie3b6516a4047717212521315e85f5e2094373cbc
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@159873 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@digia.com>