* m4/cbrtl.m4 (gl_FUNC_CBRTL_WORKS): New macro.
(gl_FUNC_CBRTL): Invoke it. If the function does not work, set
REPLACE_CBRTL to 1.
* doc/posix-functions/cbrtl.texi: Mention the OpenBSD 5.1/SPARC bug.
* m4/cbrtl-ieee.m4: New file.
* m4/cbrtl.m4 (gl_FUNC_CBRTL): If gl_FUNC_CBRTL_IEEE is present,
test whether cbrtl works with a minus zero argument. Replace it if not.
* lib/math.in.h (cbrtl): Override if REPLACE_CBRTL is 1.
* m4/math_h.m4 (gl_MATH_H_DEFAULTS): Initialize REPLACE_CBRTL.
* modules/math (Makefile.am): Substitute REPLACE_CBRTL.
* modules/cbrtl (configure.ac): Consider REPLACE_CBRTL.
(Depends-on): Update conditions.
* modules/cbrtl-ieee (Files): Add m4/cbrtl-ieee.m4, m4/minus-zero.m4,
m4/signbit.m4.
(configure.ac): Invoke gl_FUNC_CBRTL_IEEE.
* lib/cbrtl.c (cbrtl) [IRIX]: Avoid an unnecessary addition.
* doc/posix-functions/cbrtl.texi: Mention the cbrtl-ieee module.
* lib/math.in.h (cbrtl): New declaration.
* lib/cbrtl.c: New file.
* m4/cbrtl.m4: New file.
* m4/math_h.m4 (gl_MATH_H): Test whether cbrtl is declared.
(gl_MATH_H_DEFAULTS): Initialize GNULIB_CBRTL, HAVE_CBRTL,
HAVE_DECL_CBRTL.
* modules/math (Makefile.am): Substitute GNULIB_CBRTL, HAVE_CBRTL,
HAVE_DECL_CBRTL.
* modules/cbrtl: New file.
* tests/test-math-c++.cc: Check the declaration of cbrtl.
* doc/posix-functions/cbrtl.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.