[PATCH, POINTER] Let gas support mips64

[Ian Lance Taylor]

Thiemo Seufer <ica2_ts@csv.ica.uni-stuttgart.de> writes:

> 	(load_register): Change register width check to use USES_32BIT_REGS.
> 	Fix handling of sign bit in 64bit constants.

A small thing: you're changing a pair of shifts by 16 to a single
shift by 32.  That will lead to warnings when compiled on a 32 bit
processor.  That's why the shifts by 16 are there.  Also, note that
gas normally use valueT and addressT rather than bfd_vma.  (I actually
don't see any semantic change here at all, although I am probably
missing something.)

Ian