* 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.