Re: ld, gold: remove support for -z bndplt (MPX prefix)

Don't attempt to run gold tests with -z bndplt

	* testsuite/Makefile.am (exception_x86_64_bnd_test, bnd_plt_1.sh),
	(bnd_ifunc_1.sh, bnd_ifunc_2.sh): Delete rules.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/bnd_ifunc_1.s: Delete.
	* testsuite/bnd_ifunc_1.sh: Delete.
	* testsuite/bnd_ifunc_2.s: Delete.
	* testsuite/bnd_ifunc_2.sh: Delete.
	* testsuite/bnd_plt_1.s: Delete.
	* testsuite/bnd_plt_1.sh: Delete.