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.