Hello,

The attached deprecates SIGTRAMP_START and SIGTRAMP_END.  These were 
made obsolete by PC_IN_SIGTRAMP (which in turn has been made obsolete by 
signal trampoline frame sniffers).

Note that blockframe.c:find_pc_partial_function contains what I consider 
to be broken references to these macros -- typically it is only possible 
to determine the location of a signal trampoline by doing a detailed 
analysis of the inferior (i.e., unwinding frames and examining 
instructions) yet that function is ment to work with just static 
information.  I've added a comment explaining this.

comments?

I'll look to commit this in a week.

Andrew