Remove eprintf - it was needed only for ancient GCC assert.h

[emaste]

Summary

As far as I can tell:

• Prior to 2001 GCC used to provide its own assert.h
• The GCC assert.h required __eprintf to emit the error message
• FreeBSD's own assert.h never used this

so objects with references to __eprintf must have been compiled with a 15 year old GCC other than the one in the base system. I'm not sure we need to worry about that.

This came up because __eprintf references __stderrp, compilerrt_mumble, fflush and fprintf. This doesn't matter much when used as libgcc.a, although introduces a small additional link-time overhead for probably no value.

I would like to extend compiler-rt to libgcc_s.so as well, and this dependency seems silly there (even if in practice it will not be a problem).

[emaste]

From contrib/llvm-project/compiler-rt/lib/builtins/eprintf.c:

// __eprintf() was used in an old version of <assert.h>.
// It can eventually go away, but it is needed when linking
// .o files built with the old <assert.h>.
//
// It should never be exported from a dylib, so it is marked
// visibility hidden.

[emaste]

refresh

[imp]

Yea, we don't necessarily promise compatibility for this, but we could add it to a compatX if there's demand
[edited]

[emaste]

The comment in the compiler-rt implementation indicates it was only used for static linking, so this would only come up if you tried to build something on modern FreeBSD with a 20-year-old GCC.

[emaste]

Or had a .o compiled with a 20+ year old GCC that was not the one in the FreeBSD base system.