[Bug tree-optimization/93404] [13/14/15/16 regression] -O2 and -O2 -flto SPEC2006 and 2017 code size regression

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93404
Bug 93404 depends on bug 93407, which changed state.

Bug 93407 Summary: Dead partial memset not optimized away (clang does that)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93407

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