[patch]: Support coff noread flag for segments

[Dave Korn]

Kai Tietz wrote:

> So here is the patch with documentation changes, too.

  This is now OK.

> Possibly your
> testcase for .drectve we could use here in gas, too?

  I didn't think of that.  Yes, it's a good idea.  I'll extend the tests in my
patch so at least one of them uses flag "y" and checks the header flags get
set right.

    cheers,
      DaveK