This is another small H8 cleanup.  This time we're killing a peephole2
that doesn't seem terribly useful.  The peephole in question narrows a
SImode comparison to QImode when it's fed by an (and (xor)) and the
result is the same in either mode.  I couldn't get this to trigger
within libgcc, newlib or in the testsuite.  Note that we do some of
this kind of narrowing in match.pd these days, so it may be the case
that the pattern was of marginal value before and none after the
match.pd improvements.

The more straightforward SI->QI and HI->QI operand narrowing when fed
by a simple (and) operation were consolidated into a single peephole2. 
These are still triggering which may point to a failing of the match.pd
patterns, but addressing in match.pd seems terribly out of scope at
this point.

Installing on the trunk.

Jeff