Regression due to tree loop opt / expand weirdness

[Richard Kenner]

    > I can't imagine except that would break things when you *do*
    > want to use "typedef void *ptr32 __attribute__((mode(SI)));".

    What do you think would break?  I assume you're talking about
    s390x, not ia64 (as on ia64 there wouldn't be any difference).

On ia64/VMS, the default pointer size is 64 bits.  But you have to
pass 32-bit addresses to some system calls.  Hence the need to support
the above typedef.