config/gould/tmp-{pn,np1}.h,
config/{sparc/tm-sparc.h,pyr/tm-pyr.h,vax/tm-vax.h}: Remove field
next_frame from struct frame_info. It has no purpose beyond
->next->frame and is an artifact from GDB 2.8.
calling SKIP_PROLOGUE_FRAMELESS_P if it's defined.
* tm-sparc.h (SKIP_PROLOGUE, SKIP_PROLOGUE_FRAMELESS_P):
Define two variants, one faster.
* sparc-tdep.c (sparc_frame_chain): Use target_read_memory
and return zero, rather than giving an error.
(setup_arbitrary_frame): Initialize the PC in the new frame.
(skip_prologue): Add a second arg saying whether we're just
checking for a frameless function or not.
