[Bug sanitizer/87857] case label does not reduce to an integer constant

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87857

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
The reason you get an error is that the expression isn't constant, because it
needs to emit the runtime diagnostics.  Just fix the bug and get away with
that?  1U<<31 will do.