[Bug c/127765] `__builtin_stdc_rotate_left/right` with constant operands is not a constant expression for `unsigned _BitInt(N)` without a machine mode

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127765

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Note, there can be also COMPOUND_EXPRs added for -fsanitize=undefined if
ubsan_sanitize_shift can't prove everything is ok.
Note, normally ubsan_instrument_shift is called on c_fully_folded arguments,
but not in this spot.  So maybe I should call it there too.