* hppa-linux-tdep.c (hppa_linux_sigtramp_find_sigcontext): Pass in pc
instead of sp, handle sigaltstack case.
(hppa_linux_sigtramp_frame_unwind_cache): Adjust calls to
hppa_linux_sigtramp_find_sigcontext, and set base to the frame of the
signal handler and not that of the caller.
(hppa_linux_sigtramp_unwind_sniffer): Adjust calls to
hppa_linux_sigtramp_find_sigcontext.
* hppa-tdep.c (hppa_frame_prev_register_helper): New function to
do common handling of the pcoqt register.
(hppa_frame_prev_register, hppa_stub_frame_prev_register): Convert
to use helper function.
(hppa_frame_unwind_sniffer): Only use if unwind entry is present.
(hppa_fallback_frame_cache, hppa_fallback_frame_this_id)
(hppa_fallback_frame_prev_register, hppa_fallback_frame_unwind): New
generic fallback unwinder when all else fails.
(hppa_gdbarch_init): Add fallback sniffer.
* hppa-tdep.h (hppa_frame_prev_register_helper): Prototype.
* hppa-linux-tdep.c (hppa_linux_sigtramp_frame_prev_register): Convert
to use helper function.
* configure.host (hppa*-*-linux*): New target.
* configure.tgt (hppa*-*-linux*): Likewise.
* hppa-tdep.c (hppa_gdbarch_init): Set cannot_fetch_register, move
gdbarch_init_osabi() call earlier so that osabi-specific frame
unwinders can be registered first.
* config/djgpp/fnchange.lst: Add entries for hppa-linux-tdep.c and
hppa-linux-nat.c.
* config/pa/tm-hppa.h (ISR_REGNUM, PID0_REGNUM, PID1_REGNUM)
(PID2_REGNUM, PID3_REGNUM): Add definitions of some register numbers.
* config/pa/linux.mh: New file.
* config/pa/linux.mt: New file.
* config/pa/nm-linux.h: New file.
* config/pa/xm-linux.h: New file.
* hppa-linux-nat.c: New file.
* hppa-linux-tdep.c: New file.
