new gdb arch routine FRAME_UNCHANGED

[Andrew Cagney]

> On May 13,  6:46pm, Andrew Cagney wrote:
> 
> 
>> Also, code wants to determine which code is more INNER_THAN().  With two 
>> stacks, that starts to get really weird!
> 
> 
> Yes.  On IA-64, the meaning of INNER_THAN is different for the two stacks.
> (I.e, the stacks grow in different directions.)
> 
> Kevin

My brain hurts!  This is increasingly like floating point with +0 != -0. 
  We have a situtation where for:

	frame_id a, b; // contain both SP's and PC

the test:

	!FRAME_ID_INNER_THAN(a,b) && !FRAME_INNER_THAN(b,a)

does not imply

	FRAME_ID_SAME(a,b)

(or what ever the functions are called).

Andrew