New mn10300 cmpsi breaks reload

[Alexandre Oliva]

Reload assumes that, when one operand is to match another, one of them
must be for input and the other must be for output.  No exceptions.
It has been like that forever (25-mar-91, as per the CVS log).  I
don't understand how this didn't break for you, Matt, but I've just
noticed it's broken now.  Perhaps it's some side effect or subreg byte
or something else, I don't know.  But it can't even build libgcc now.

Here's a patch that fixes this.  Sorry for having led you the wrong
path (I was the one who had suggested removing the `!'s :-(

I'm checking this in.