[Bug d/88462] All D execution tests FAIL on Solaris/SPARC

["ibuclaw at gdcproject dot org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88462

--- Comment #12 from Iain Buclaw <ibuclaw at gdcproject dot org> ---
(In reply to Johannes Pfau from comment #10)
> I guess the proper fix to the alignment problem is using
> 'https://dlang.org/phobos/std_traits.html#classInstanceAlignment' (or rather
> the druntime equivalent) instead of Mutex.alignof + the rounding / slice
> assignment fixes?
> 
> Regarding the ModuleInfo problem: Although ModuleInfo does have a variable
> size, _flags ist the first field in the struct. So the whole struct instance
> has to be misaligned for some reason? Is the minfo section aligned properly?

ModuleInfo is forced an alignment of 1.  It should be instead aligned to
`max(uint.sizeof, size_t.sizeof)` so that both named and variable data parts
can be read without alignment problems.