For various reasons, it can be useful/interesting to create builds of
Swift that minimize dependencies. Let's try to keep that working as long
as we can.
Module references get indexed as a 'module' symbol; they get USRs similar to how clang would assign a USR for a module reference.
JIRA: https://bugs.swift.org/browse/SR-8677
This makes the tests more focused on what they are interested in testing
and allows flexibility on changing dependency printing on the clang side
without breaking the swift tests.
This converts the instances of the pattern for which we have a proper
substitution in lit. This will make it easier to replace it
appropriately with Windows equivalents.
