This is (far) from robust -- particularly with repeated compiles in the
same address space. But it appears to be sufficient in the short term,
and we already have the relevant TODOs to factor this upstream into
something that we can use here.
This also somehow uncovered a bug in how we were logging failed commands
-- the failed commands are destroyed when we destroy the driver object
(and its diagnostics object), so we simply cannot do the logging _after_
flushing diagnostics. That's probably ok, and just doing this in the
other order makes the code simpler.
Assisted-by: Antigravity with Gemini
Chandler Carruth
b16cde9c53