Build ifunc tests when non-native

Plus a number of fixes to the pr23169 tests.

	* testsuite/lib/ld-lib.exp (check_ifunc_available): Pass without
	running executable when non-native.
	(check_ifunc_attribute_available): Likewise.
	* testsuite/ld-ifunc/pr23169a.rd: Remove extraneous lines.  Match
	st_other strings.  Pass when func is an ifunc.
	* testsuite/ld-ifunc/pr23169b.rd: Remove extraneous lines.  Correct
	reloc regexp.  Correct match-anything line.
	* testsuite/ld-ifunc/pr23169c.rd: Remove extraneous lines.  Match
	st_other strings.