[Bug rtl-optimization/108516] Useless movzx instruction emitted when loading 8 bits from 24 bit struct

[levo.delellis at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108516

--- Comment #5 from Levo DeLellis <levo.delellis at gmail dot com> ---
Here's a testcase for the same problem

        struct T2 { bool a, b; };
        static T2 test();
        int myfunc() {
                auto [a, b] = test();
                return ((int)a<<1) + b;
        }