Use variable args in run_ld_link_exec_tests

Use variable args in run_ld_link_exec_tests

If the last parameter of a tcl function is "args" then it can take
zero or more arguments.  Make use of this language feature in
run_ld_link_exec_tests.

	* testsuite/lib/ld-lib.exp (run_ld_link_exec_tests): Replace
	"targets_to_xfail" parameter with "args".
	* testsuite/ld-elf/compress.exp: Remove empty list of xfails on
	all calls to run_ld_link_exec_tests.
	* testsuite/ld-elf/dwarf.exp: Likewise.
	* testsuite/ld-elf/indirect.exp: Likewise.
	* testsuite/ld-elf/wrap.exp: Likewise.
	* testsuite/ld-i386/i386.exp: Likewise.
	* testsuite/ld-i386/no-plt.exp: Likewise.
	* testsuite/ld-i386/tls.exp: Likewise.
	* testsuite/ld-ifunc/ifunc.exp: Likewise.
	* testsuite/ld-pie/pie.exp: Likewise.
	* testsuite/ld-plugin/lto.exp: Likewise.
	* testsuite/ld-size/size.exp: Likewise.
	* testsuite/ld-x86-64/mpx.exp: Likewise.
	* testsuite/ld-x86-64/no-plt.exp: Likewise.
	* testsuite/ld-x86-64/tls.exp: Likewise.
	* testsuite/ld-x86-64/x86-64.exp: Likewise.
	* testsuite/ld-elf/elf.exp: Likewise.  Reorder args when providing
	xfails and simplify lists.
	* testsuite/ld-elf/shared.exp: Likewise.