#270 fails to compile on freebsd, no MAP_32BIT defined

[Julian Taylor]

pearpc 0.5.0 does not build on freebsd kernels due to the lack of MAP_32BIT

g++ -DHAVE_CONFIG_H -I. -I../../.. -I ../.. -Wundef -Wall -Woverloaded-virtual -fsigned-char -O3 -fomit-frame-pointer -g -fno-inline -pthread -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pipe -I/usr/include/SDL -D_GNU_SOURCE=1 -D_REENTRANT -c -o ppc_mmu.o ppc_mmu.cc
ppc_mmu.cc: In function 'bool ppc_init_physical_memory(uint)':
ppc_mmu.cc:828:84: error: 'MAP_32BIT' was not declared in this scope
make[5]: *** [ppc_mmu.o] Error 1

Is it safe to just remove the flag (or define it to 0) like in sysvm.c where its used too?
I'm not familiar if a similar flag exists for bsd.

see the bug in debian:
http://bugs.debian.org/cgi-bin/bugreport.cgi?archive=no&bug=651626