New module 'ceil-ieee'.

New module 'ceil-ieee'.

* modules/ceil-ieee: New file.
* m4/ceil.m4 (gl_FUNC_CEIL): Require gl_MATH_H_DEFAULTS. If
gl_FUNC_CEIL_IEEE is also used, test whether ceil works according to
ISO C 99 with IEC 60559.
* m4/ceil-ieee.m4: New file.
* modules/ceil (Files): Add lib/ceil.c.
(Depends-on): Add 'float'.
(configure.ac): Invoke gl_MATH_MODULE_INDICATOR.
* lib/math.in.h (ceil): New declaration.
* m4/math_h.m4 (gl_MATH_H_DEFAULTS): Initialize GNULIB_CEIL,
REPLACE_CEIL.
* modules/math (Makefile.am): Substitute GNULIB_CEIL, REPLACE_CEIL.
* modules/ceil-ieee-tests: New file.
* tests/test-ceil-ieee.c: New file, based on tests/test-ceilf-ieee.c.
* tests/test-math-c++.cc: Check the signature of 'ceil'.
* doc/posix-functions/ceil.texi: Mention the new module.