[Bug tree-optimization/99396] std::rotl and std::rotr Does not convert into ROTATE on the gimple level

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99396

--- Comment #10 from Jonathan Wakely <redi at gcc dot gnu.org> ---
As you noted on IRC, these functions are undefined for anything except unsigned
integral types. Adding that here for observers wondering about comments 7 and
8.