ld/x86: reduce testsuite dependency on system object files

PR ld/30722
Tests looking for certain .note-section recorded properties may not
involve object files from the underlying platform (e.g. via using the C
compiler for linking): Such object files may themselves have similar
note sections, and hence they may influence the overall outcome.

For now convert just the tests known to be affected by crt*.o coming
with "ISA v3 needed" notes. Eventually other tests ought to be
converted, too.