Skip ld/lto tests if plugins is disabled for binutils?

[Bin.Cheng]

Hi,
I found there are some FAIL ld test cases with message like "sorry -
this program has been built without plugin support", and the program
in this case is ar.  I think it's because I configured/built binutils
without "--enable-plugins", the question is:
should we skip these kind of tests if plugins isn't enabled?

I don't know much about ld/lto tests, so please correct if I was wrong.

Thanks,
bin