Patch to allow Ada to work with tree-ssa

[Richard Kenner]

    Though I've not been able to fully analyse it, very likely
    this is the patch that is causing 2 new FAILs for libjava
    on i686-pc-linux-gnu. (If not, I apologise in advance.)

Could well be. 
        
    The testcase is "libjava/testsuite/libjava.lang/err6.java"
    and is reproduced here for your reference:

Could I ask for somebody's help here?  I don't even know the Java language,
let alone the Java front end.

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

Thanks.