(TARGET_HAS_HARDWARE_WATCHPOINTS, etc): Define as for Irix 4;
from Lee Iverson <leei@ai.sri.com>.
* config/mips/irix5.mh (NAT_FILE): Use nm-irix5.h.
* config/mips/irix[345].mh (MUNCH_DEFINE): Remove.
config files moved to an appropriate config/<cpu> subdirectory.
* nm-*, xm-*, tm-*: All native, host, and target files, which
get linked to nm.h, xm.h, and tm.h respectively by configure,
moved to appropriate config/<cpu> subdirectory.