* lib/autoconf/programs.m4 (AC_PATH_TOOL, AC_CHECK_TOOL,
AC_CHECK_TOOLS): Warn if a cross-tool is found without
a prefix.
(AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOL,
AC_CHECK_TARGET_TOOLS): New macros.
* doc/autoconf.texi (Generic Programs): Document
(AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOL,
AC_CHECK_TARGET_TOOLS, and warn for future changes
in the behavior of AC_PATH_TOOL, AC_CHECK_TOOL and
AC_CHECK_TOOLS.
(Specifying Names): Document the reason for these future
behavioral changes.
* tests/mktests.sh: Do not generate tests for the
new macros.
* NEWS: Document these changes.
* doc/autoconf.texi: Avoid macros with unbraced arguments,
they make TeX hang up.