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

ok kettenis@ millert@ deraadt@

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 complex math routines, now that we have the
extended-precision support. Mostly from Cephes.

- replace dtoa w/ David's gdtoa, version 2008-03-15
- provide proper dtoa locks
- use the real strtof implementation
- add strtold, __hdtoa, __hldtoa
- add %a/%A support
- don't lose precision in printf, don't round to double anymore
- implement extended-precision versions of libc functions: fpclassify,
isnan, isinf, signbit, isnormal, isfinite, now that the ieee.h is
fixed
- separate vax versions of strtof, and __hdtoa
- add complex math support. added functions: cacos, casin, catan,
ccos, csin, ctan, cacosh, casinh, catanh, ccosh, csinh, ctanh, cexp,
clog, cabs, cpow, csqrt, carg, cimag, conj, cproj, creal, cacosf,
casinf, catanf, ccosf, csinf, ctanf, cacoshf, casinhf, catanhf,
ccoshf, csinhf, ctanhf, cexpf, clogf, cabsf, cpowf, csqrtf, cargf,
cimagf, conjf, cprojf, crealf
- add fdim, fmax, fmin
- add log2. (adapted implementation e_log.c. could be more acruate
& faster, but it's good enough for now)
- remove wrappers & cruft in libm, supposed to work-around mistakes
in SVID, etc.; use ieee versions. fixes issues in python 2.6 for
djm@
- make _digittoint static
- proper definitions for i386, and amd64 in ieee.h
- sh, powerpc don't really have extended-precision
- add missing definitions for mips64 (quad), m{6,8}k (96-bit) float.h
for LDBL_*
- merge lead to frac for m{6,8}k, for gdtoa to work properly
- add FRAC*BITS & EXT_TO_ARRAY32 definitions in ieee.h, for hdtoa&ldtoa
to use
- add EXT_IMPLICIT_NBIT definition, which indicates implicit
normalization bit
- add regression tests for libc: fpclassify and printf
- arith.h & gd_qnan.h definitions
- update ieee.h: hppa doesn't have quad-precision, hppa64 does
- add missing prototypes to gdtoaimp
- on 64-bit platforms make sure gdtoa doesn't use a long when it
really wants an int
- etc., what i may have forgotten...
- bump libm major, due to removed&changed symbols
- no libc bump, since this is riding on djm's libc major crank from
a day ago

discussed with / requested by / testing theo, sthen@, djm@, jsg@,
merdely@, jsing@, tedu@, brad@, jakemsr@, and others.
looks good to millert@
parts of the diff ok kettenis@

this commit does not include:
- man page changes