Last alignment change for MEM tracking

[Richard Kenner]

    One problem I've noticed in optabs.c is the calls to gen_cmpstrxx are
    passing the wrong argument type for the 5th paramater which requires
    a (rtx) but is being passed an (unsigned int).

Oops.  This is OK.

    Unfortunately this still doesn't get us back to bootstrap land on x86.

I have a fix for that which should be checked in in under 20 minutes.