[Bug tree-optimization/120206] Removal of forward_propagate_into_gimple_cond/forward_propagate_into_comparison

[pzheng at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120206
Bug 120206 depends on bug 123109, which changed state.

Bug 123109 Summary: `a >> (bits-1) != 0` is not optimized to `a < 0` by match
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123109

           What    |Removed                     |Added
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             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED