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

[Eric Botcazou]

> I see no value in blindly allowing relocations to overflow when we
> know that when it occurs something is very wrong.  Failing and
> emitting an error is the right thing for 'ld' to do.

The consensus for years has been to silently accept this, so turning the tables 
in 2012 doesn't make much sense I think.  It's just debug info after all.

-- 
Eric Botcazou