It's been a quarter century: we can assume volatile is present with that name.

bring in math.h to provide prototypes

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@.

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

Revert (leaving the complex math part alone). Some stuff is depending
on this historical behavior; so we're stuck in this stupid situation.
No cookie for me.

Move fabs(3), frexp(3), and modf(3) to libm--nothing has been using
them in libc for a very long time. OK guenther@.

use sys/cdefs.h

alias fabsl to fabs on these archs

make an ieeefp regress pass; miod@ ok

I was on drugs when I commited this initially, and still do not understand
how I got libc to compile with this. Blush.

Replace this with a correct implementation, and write a faster fabs()
while there.

ok mickey@

More fp-related libc pieces for hppa.
This enables awk to link.