[arm] Fix thumb -fPIC

[Richard Earnshaw]

On Fri, 2004-10-01 at 16:45, Paul Brook wrote:
> Patch below fixes a couple of bugswhen generating thumb PIC code.
> One we are ORing with a register number rather than a bitmask. the other we 
> weren't searching all low regs when looking for a work register.
> 
> Tested with cross to arm-none-elf.
> Applied as obvious to csl-arm-branch and mainline as this has been discussed 
> before.
> 
> Paul
> 
> 2004-01-01  Paul Brook  <paul@codesourcery.com>
> 
>  * config/arm/arm.c (thumb_compute_saved_rag_mask): Or with bitmask,
>  not register number.
>  (thumb_find_work_register): Search full register range.

I'm not 100% sure about the second issue.  LAST_LO_REGNUM is sometimes
used as a frame pointer register when we can't manage without one, have
you checked that it's safe to use it as a scratch in these conditions
(it may be, but I'm not sure).

Other part is OK.

R.