From #148554 - compile tests with exceptions on Windows
(`-fno-exceptions` was added 11 years ago in
c7826524acda6a9c8816261d5c48b94dc92935ed). The variant test uses `try {}
catch {}` to create variants that are valueless by exception. On other
platforms, exceptions are enabled as well.
I have no clue why compiling with exceptions will optimize out
`a_long_guy` in the changed test (even with `-O0`). Taking the address
of that value will ensure it's kept.