ldscripts/empty-address vs. xcoff

ldscripts/empty-address vs. xcoff

The empty-address tests check that if a section is removed by ld due
to being empty then properties of that section don't affect following
addresses.  The xcoff backend doesn't remove the empty .data section
created by empty-address-2* and empty-address-3* for some reason, and
therefore fails the test.

	* testsuite/ld-scripts/empty-address-1.d: Accept more symbols.
	* testsuite/ld-scripts/empty-address-2a.d: xfail for xcoff.
	* testsuite/ld-scripts/empty-address-2b.d: Likewise.
	* testsuite/ld-scripts/empty-address-3a.d: Likewise.
	* testsuite/ld-scripts/empty-address-3b.d: Likewise.