Could IWMMXT_GR_REGS be contained by ALL_REGS in ARM back end?

[Xinyu Qi]

Hi,

  Some one point out the root cause for the bug 54338 
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54338
is that the IWMMXT_GR_REGS is not contained in ALL_REGS so that an assertion 
fail is triggered in front end.
  I checked the macro REG_CLASS_CONTENTS in arm.h and confirmed it.
  This ICE could be fixed if make ALL_REGS contain IWMMXT_GR_REGS.
  Is there any concerns that IWMMXT_GR_REGS shouldn't be included in ALL_REGS?

Thanks,
Xinyu