* lib/math.in.h (expm1l): Test HAVE_DECL_EXPM1L, not HAVE_EXPM1L.
* m4/expm1l.m4 (gl_FUNC_EXPM1L): Don't assume expm1l() is declared when
it exists. Set HAVE_DECL_EXPM1L.
* m4/math_h.m4 (gl_MATH_H_DEFAULTS): Initialize HAVE_DECL_EXPM1L, not
HAVE_EXPM1L.
* modules/math (Makefile.am): Substitute HAVE_DECL_EXPM1L, not
HAVE_EXPM1L.
* doc/posix-functions/expm1l.texi: Mention missing declaration problem.
* lib/math.in.h (expm1l): New declaration.
* lib/expm1l.c: New file.
* m4/expm1l.m4: New file.
* m4/math_h.m4 (gl_MATH_H): Test whether expm1l is declared.
(gl_MATH_H_DEFAULTS): Initialize GNULIB_EXPM1L, HAVE_EXPM1L.
* modules/math (Makefile.am): Substitute GNULIB_EXPM1L, HAVE_EXPM1L.
* modules/expm1l: New file.
* tests/test-math-c++.cc: Check the declaration of expm1l.
* doc/posix-functions/expm1l.texi: Mention the new module.
* 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.