* m4/exp2l-ieee.m4: New file.
* m4/exp2l.m4 (gl_FUNC_EXP2L): If gl_FUNC_EXP2L_IEEE is present,
test whether exp2l works with a NaN argument and with a negative
infinity argument. Replace it if not.
* lib/math.in.h (exp2l): Override if REPLACE_EXP2L is 1.
* m4/math_h.m4 (gl_MATH_H_DEFAULTS): Initialize REPLACE_EXP2L.
* modules/math (Makefile.am): Substitute REPLACE_EXP2L.
* modules/exp2l (configure.ac): Consider REPLACE_EXP2L.
(Depends-on): Update conditions.
* modules/exp2l-ieee (Files): Add m4/exp2l-ieee.m4.
(configure.ac): Invoke gl_FUNC_EXP2L_IEEE.
* doc/posix-functions/exp2l.texi: Mention the exp2l-ieee module.
* lib/math.in.h (exp2l): New declaration.
* lib/exp2l.c: New file.
* lib/expl-table.c: New file, extracted from lib/expl.c.
* lib/expl.c (gl_expl_table): New declaration.
(expl): Remove expl_table. Update reference.
* m4/exp2l.m4: New file.
* m4/math_h.m4 (gl_MATH_H): Test whether exp2l is declared.
(gl_MATH_H_DEFAULTS): Initialize GNULIB_EXP2L, HAVE_DECL_EXP2L.
* modules/math (Makefile.am): Substitute GNULIB_EXP2L, HAVE_DECL_EXP2L.
* modules/exp2l: New file.
* modules/expl (Files): Add lib/expl-table.c.
(configure.ac): Compile also expl-table.c.
* tests/test-math-c++.cc: Check the declaration of exp2l.
* doc/posix-functions/exp2l.texi: Mention the new module and the IRIX
problem.
* m4/printf.m4 (gl_PRINTF_INFINITE_LONG_DOUBLE): Don't guess yes on
NetBSD; the test fails on NetBSD 5.0.
* doc/{glibc,posix,pastposix}-{headers,functions}/*.texi: Update info
about NetBSD.
