Force -fno-sibling-call-optimisation to every module's CFLAGs. This fixes *numerous...
drwxr-xr-x - cis
drwxr-xr-x - irc
drwxr-xr-x - msvc6
drwxr-xr-x - os2
drwxr-xr-x - reactos
drwxr-xr-x - rosapps
drwxr-xr-x - rosky
drwxr-xr-x - vms