logf: Work around OSF/1 5.1 bug. * lib/math.in.h (logf): Override if REPLACE_LOGF is 1. * lib/logf.c (logf): If logf exists, use it and provide just the workaround. * m4/logf.m4 (gl_FUNC_LOGF_WORKS): New macro. (gl_FUNC_LOGF): Invoke it. Set REPLACE_LOGF. * m4/math_h.m4 (gl_MATH_H_DEFAULTS): Initialize REPLACE_LOGF. * modules/math (Makefile.am): Substitute REPLACE_LOGF. * modules/logf (configure.ac): Consider REPLACE_LOGF. (Depends-on): Update conditions. * doc/posix-functions/logf.texi: Mention the OSF/1 5.1 problem.

# See lib/git-merge-changelog.c for making this useful.
ChangeLog	merge=merge-changelog

# Run this to make 'git diff' on texinfo files give nicer hunk context:
#   git config diff.texinfo.funcname '^@node[	 ][	 ]*\\([^,][^,]*\\)'
*.texi* diff=texinfo