[Bug c/82210] [6/7/8 Regression] Having _Alignas in a struct with VLAs causes writing to one array to overwrite another

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82210

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
The difference with that revision is:
        addq    $2, %rax
        cmpq    %rcx, %rax
        jne     .L3
-       leaq    (%r12,%rdx), %rdx
+       andq    $-16, %rdx
        xorl    %eax, %eax
+       leaq    (%r12,%rdx), %rdx