Reduce libm's exports and make internal calls go direct.
All dependencies on libc are now via reserved/standardized names.

ok kettenis@ millert@ deraadt@

Add parentheses around comparison in operand of ^. Pointed out by theo.

test LDBL_MANT_DIG == DBL_MANT_DIG instead of hardcoding 53.
-> test becomes meaningful on vax
No actual change, no bump
okay martynas@

Switch libc and libm to use strong aliases rather than weak aliases
where appropriate. Among other things makes the symbols consistent
across all architectures (notably where ldbl mantissa is 53 bits).

While at it, kill unused LINTLIBRARY/PROTOLIB1 cruft which was there
to trick lint into recording the right prototypes for aliased
functions. Most of the work done at the awesome n2k13 hackathon.

Agreed by kettenis@, guenther@, matthew@.

Get rid of the very ugly lint workarounds: LINTLIBRARY, PROTOLIB,
and a few empty files for lint to chew on.

Remove excessive sys/cdefs.h inclusion
ok guenther millert kettenis

Finalize work on the math library. It's time to do this monster
commit, and deal with problems (if any) in tree.

Note that this adds the following functions. Ports with hacks might
need adjustments.

nexttoward(3), fma(3), nexttowardf(3), fmaf(3), acoshl(3), asinhl(3),
atanhl(3), coshl(3), sinhl(3), tanhl(3), expl(3), expm1l(3), logl(3),
log10l(3), log1pl(3), log2l(3), modfl(3), cbrtl(3), hypotl(3),
powl(3), erfl(3), erfcl(3), lgammal(3), tgammal(3), ceill(3),
floorl(3), lrintl(3), llrintl(3), roundl(3), lroundl(3), llroundl(3),
truncl(3), fmodl(3), remainderl(3), remquol(3), nextafterl(3),
nexttowardl(3), fmal(3).

With this commit, our library implements all functionality required
by C99. Documentation bits will follow.