[Bug tree-optimization/88854] redundant store after load that would makes aliasing UB

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88854

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Causes

FAIL: gcc.dg/tree-ssa/ssa-pre-30.c scan-tree-dump-times pre "Replaced MEM" 2

the extra entry somehow confuses PRE (AVAIL compute I guess).