fix the framework error

fix the framework error

Running the testsuite for an x86_64-w64-mingw32 target using the
Ubuntu package gcc-mingw-w64-x86-64 version 13.2.0-6ubuntu1+26.1
results in a number of messages:
ERROR: can't decipher gcc version number, fix the framework!

Someone in their wisdom decided this compiler should advertise itself
with a version of 13-win32, breaking the ld testsuite version checks.
(It is also configured using --with-as=/usr/bin/x86_64-w64-mingw32-as
--with-ld=/usr/bin/x86_64-w64-mingw32-ld which renders the -B flag
inoperative for testing the newly built gas and ld.  You'd need to
install binutils over the top of the Ubuntu versions before testing, a
rather unsatisfactory process.)

	* testsuite/lib/ld-lib.exp (at_least_gcc_version): Use
	preprocessor test of __GNUC__ and __GNUC_MINOR__ rather than
	output of gcc --version.  Correct removal of -Wl options.