Real purpose for failure in "Too restrictive sanity check"

[Richard Kenner]

    It breaks Alpha too.

No, actually the bug is in CSE and has been there forever.  This just
triggers it!  I found this yesterday evening, but the bootstrap didn't finish
before I went to sleep.

    which is wrong.  The notes must be limited to function-wide invariants.

No, that's true for REG_EQUIV, but not REQ_EQUAL.  I''ll commit my
patch to the real problem and you can put this one back.