Compile log output is now separated based on the `AnalUnit` which
perfomred the `@compileLog` call, so that we can omit the output for
unreferenced ("dead") units. The units are also sorted when collecting
the `ErrorBundle`, so that compile logs are always printed in a
consistent order, like compile errors are. This is important not only
for incremental compilation, but also for parallel analysis.
Resolves: #23609
These cases have been disabled for a while, and we have transitioned to
using a compact file format for incremental test cases.
I was originally planning to port all of these cases, but the vast
majority aren't testing anything interesting, so it wasn't worth the
effort. I did look through each one; anything interesting being tested
has been extracted into a new case in `test/incremental/`.
Two of the new tests are currently failing with the self-hosted ELF
linker, and thus are currently only enabled with the C backend.
Resolves: #12844
