0cf69f0 introduced a kms-divergence-check Evergreen task that checks whether the KMS sources in libmongoc and libmongocrypt diverge. More context from roberto.sanchez@mongodb.com:

It is defined here, assigned to a build variant here, and executes this script (example run here.

Based on a recent conflict between the "mlib" headers in libmongoc and libmongocrypt (addressed in MONGOCRYPT-845), I propose creating a separate task that checks for possible naming collisions between sub-directories and/or headers in both libraries. We can also consider checking for symbol conflicts, but filenames are probably a good first step.