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.
