* libc/stdlib/gdtoa-hexnan.c (hexnan): When the optional
n-char-sequence is omitted, still parse the ().
-------------------------------------------------------------------
* libc/stdlib/Makefile.am: Add new gdtoa routines.
* libc/stdlib/Makefile.in: Regenerated.
* libc/stdlib/gd_qnan.h: New file.
* libc/stdlib/gdtoa-gethex.c: Ditto.
* libc/stdlib/gdtoa-hexnan.c: Ditto.
* libc/stdlib/gdtoa.h: Ditto.
* libc/stdlib/mprec.c: Add new helper routines needed by
the new gdtoa code.
* libc/stdlib/mprec.h: Integrate some defines and prototypes
used by gdtoa routines here.
* libc/stdlib/strtod.c: Rebased on David M. Gay's gdtoa-strtod.c
which adds C99 support such as nan, inf, and hexadecimal input
format.
