Add Solaris BCP (the part of Solaris which allows it to run
SunOS4 a.out files) core file handling.
* aoutf1.h (external_solaris_bcp_core, swapcore_solaris_bcp):
New structure and its swap in function.
(internal_sunos_core): New member c_data_addr, to receive the
start address of the data section in the core file.
(swapcore_sun3, swapcore_sparc, sunos4_core_file_p): Use it.
(sunos4_core_file_p): Recognize Solaris BCP core file.
(sunos4_core_file_matches_executable_p): Always indicate match
for Solaris BCP core files.