add code to compile compat.so to provide *_chk functions for musl

add code to compile compat.so to provide *_chk functions for musl

the DF 0.43.05 x86_64 binary was apparently compiled some security/debugging
feature such as -DFORTIFY_SOURCE=2 or similar, instead of optimized solely
for highest performance, so it makes use of some glibc specific
functions that are not yet available in mainstream musl.

Error relocating ./libs/Dwarf_Fortress: __stpcpy_chk: symbol not found
Error relocating ./libs/Dwarf_Fortress: __memcpy_chk: symbol not found
Error relocating ./libs/Dwarf_Fortress: __memmove_chk: symbol not found
Error relocating ./libs/Dwarf_Fortress: __strcat_chk: symbol not found
Error relocating ./libs/Dwarf_Fortress: __strcpy_chk: symbol not found
Error relocating ./libs/Dwarf_Fortress: __memset_chk: symbol not found

in order to supply these functions we must LD_PRELOAD a .so that provides
these functions.