localrepo: move requirements reasonability testing to own function...
localrepo: move requirements reasonability testing to own function
Just because we know how to handle each listed requirement doesn't
mean that set of requirements is reasonable.
This commit introduces an extension-wrappable function to validate
that a set of requirements makes sense.
We could combine this with ensurerequirementsrecognized(). But I think
having a line between basic membership testing and compatibility
checking is more powerful as it will help differentiate between
missing support and buggy behavior.
Differential Revision:
https://phab.mercurial-scm.org/D4571
