Patch to allow Ada to work with tree-ssa

[Richard Kenner]

     > I somebody could point out what tree transformation is going wrong, I'll
     > be glad to fix it.

    It seems that something has changed the depth-first, left-to-right
    parsing of expressions.  Have you any idea what might have caused this?

"parsing"?  Did you mean gimplifying?

Indeed a number of things I did might have had the effect of changing
the order in which subtrees are gimplified.  Since I didn't think that
anything depended on that, I didn't pay that much attention to the issue.
If there are places that do depend on that, can you identify them so
that comments can be placed in gimplify.c saying what's order-dependent.

The changes would mostly relate to the order of gimplification of MODIFY_EXPR
and certain compound values, I'd guess.

Can you give an example of an expression that's handled differently?