compile glibc without most features

[Roland McGrath]

For something like an embedded use, what you would want to do is a port of
glibc supporting the embedded case as you would support a different
operating system.  This has been done in the past, for e.g. the
"arm-*-none" configuration and once upon a time there were some others.
joel.sherrill@OARcorp.com did some work for several such targets quite a
long time ago; see sysdeps/standalone for some of that work.