gcc: sync top-level with binutils-gdb

gcc: sync top-level with binutils-gdb

This just pulls in Alan's:

commit 87b6078fc212ccba5f043399c6370ee20f6b355a
Author:     Alan Modra <amodra@gmail.com>
AuthorDate: Mon Nov 3 10:59:50 2025 +1030
Commit:     Alan Modra <amodra@gmail.com>
CommitDate: Mon Nov 3 10:59:50 2025 +1030

    tidy m4 plugin config support

    ...

It tidies up the configure test output.

config/ChangeLog:

	* clang-plugin.m4: Sync with binutils.
	* gcc-plugin.m4: Ditto.

ChangeLog:

	* configure: Regenerate.

gcc/ChangeLog:

	* configure: Regenerate.

libatomic/ChangeLog:

	* configure: Regenerate.

libbacktrace/ChangeLog:

	* configure: Regenerate.

libcc1/ChangeLog:

	* configure: Regenerate.

libffi/ChangeLog:

	* configure: Regenerate.

libgcobol/ChangeLog:

	* configure: Regenerate.

libgfortran/ChangeLog:

	* configure: Regenerate.

libgm2/ChangeLog:

	* configure: Regenerate.

libgomp/ChangeLog:

	* configure: Regenerate.

libgrust/ChangeLog:

	* configure: Regenerate.

libiberty/ChangeLog:

	* configure: Regenerate.

libitm/ChangeLog:

	* configure: Regenerate.

libobjc/ChangeLog:

	* configure: Regenerate.

libphobos/ChangeLog:

	* configure: Regenerate.

libquadmath/ChangeLog:

	* configure: Regenerate.

libsanitizer/ChangeLog:

	* configure: Regenerate.

libssp/ChangeLog:

	* configure: Regenerate.

libstdc++-v3/ChangeLog:

	* configure: Regenerate.

libvtv/ChangeLog:

	* configure: Regenerate.

lto-plugin/ChangeLog:

	* configure: Regenerate.

zlib/ChangeLog:

	* configure: Regenerate.