[Bug tree-optimization/101187] enhancement for vector logic right shift with constant bigger than element precision

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101187

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
To make sure we diagnose it and catch it in ubsan and FE constant expression
folding.  The folding of the shift count into constant can happen almost any
time during the optimizations.
For ubsan and FE constant expression folding likely all that is needed is that
it is in match.pd GIMPLE only, because constexpr evaluation can use match.pd
folding and ubsan shifts are instrumented in the FEs, but for the diagnostics
not.