autotools: correct host_os os2-emx checks
autotools: correct host_os os2-emx checks
autotools: correct host_os os2-emx checks
update OS2 EMX makefiles for KLIBC environment.
net_sys.h: fix build OS/2 KLIBC builds.
minor update to makefiles, remove the unnecessary use of -std=gnu11 flag
filenames.h: added missed char* casts for C23 in previous commit.
filenames.h: added missed char* casts for C23 in previous commit.