* lib/linux+gnu.c (getuid, getdid): New function. * lib/binutils.c (getuid, getdid): Remove stub.
* lib/linux+gnu.c (getpid, signal): New function. * include/signal.h: Declare signal. * include/unistd.h: Declare getpid. * scaffold/tests/95-signal.c: Test it. * build-aux/check-mescc.sh (tests): Run it.
* lib/glibc.c: New file. * lib/libc+gnu.c: Include it.