[RFA] [pei-386] prevent ld (auto-import) from generating broken code

[DJ Delorie]

Ok, I'm cynical of the average user.  How about this:

stringtest.o: In function `main':
/usr/src/binutils/tmp/stringtest.c:9: variable 'hwstr1' can't be
auto-imported.  Please read the documentation for ld's
--enable-auto-import for details.

By not hinting at workarounds in the message, we force them to read
the more complete documentation of the issue.  And teach them to read
documentation in general too ;-)