Avoid 64-bit Solaris/SPARC -gstabs link failures (PR ld/12152)

[Ian Lance Taylor]

Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE> writes:

> An alternative
> would be to skip 64-bit -gstabs* testing, of course.

Since 64-bit -gstabs won't actually work in practice, it seems
preferable that the tests not run or, if run, fail.

Patching the programs so that the tests will pass even though nobody can
actually use the feature seems counter-productive.

Ian