Log Message:
devel/gnustep-objc: Fix unusable libobjc being produced when PKGSRC_MKPIE is set \ 
to yes (default)

Do not override CMAKE_C_COMPILER or CMAKE_CXX_COMPILER. Doing so causes
cmake to ignore cwrappers and try compiling test executables without -fPIC,
which fails, and the resulting libobjc.so will not contain any symbols from
${WRKSRC}/objcxx_eh.cc even though it still has (undefined) references to
them, e.g. test_eh_personality. devel/gnustep-base, or anything requiring
libobjc.so, will choke on missing symbols and fail to link.