[Bug middle-end/19987] [meta-bug] fold missing optimizations in general

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=19987
Bug 19987 depends on bug 96929, which changed state.

Bug 96929 Summary: Failure to optimize right shift of -1 to -1
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96929

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