Consolidates both main libraries into `//testing/base`, and factors out
the exe path handling for benchmarks and unit tests into a common
library to remove duplication. Refactors how that logic is managed to be
cleaner and avoid a confusing bool that came up in code review.
Updates all the tests and benchmarks that use these. I still need to
update other benchmarks to use the same main, but I wanted to keep this
PR somewhat minimal.
This also fixes a bug noticed in passing that the compilation benchmark
didn't have the required dependency on the benchmark library itself,
just the benchmark main library.
Chandler Carruth
72cb9d0d06