[Bug c/116457] Add -frandomize-layout-seed and -frandomize-layout-seed-file

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116457

--- Comment #1 from Sam James <sjames at gcc dot gnu.org> ---
(In reply to Sam James from comment #0)
> Clang implemented -frandomize-layout-seed and -frandomize-layout-seed-file
> instead.

... with the `randomize_layout` struct attribute.