[tree-ssa] Analysis of testsuite differences

[Andrew Pinski]

> gcc/testsuite/g++.old-deja/g++.bugs/900205_03.C
> gcc/testsuite/g++.old-deja/g++.mike/p646.C

The above two are due to the return warning/error
not happing at -O0, again this is PR 14107.


> gcc/testsuite/g++.dg/parse/stack1.C

This is PR 12454.

Thanks,
Andrew Pinski