Since compiler may pass --as-needed to ld by default, link
tmpdir/copyreloc-main.o before tmpdir/copyreloc-lib.so.
* testsuite/ld-i386/i386.exp: Link tmpdir/copyreloc-main.o
before tmpdir/copyreloc-lib.so and test --as-needed.
* testsuite/ld-x86-64/x86-64.exp: Likewise.
