Use IncludeTreeFileList instead of full feature CASFS for swift
dependency filesystem. This allows smaller CAS based VFS that is smaller
and faster. This is enabled by the CAS enabled compilation does not
need to iterate file system.
rdar://136787368
This is a regression causing lots of cached diagnostics tests not
functioning since the cached diagnostics processors are not initialized
for those tests which are supposed to test diagnostics caching.
The regression is caused by the fix that the typecheck module interface
job need to run a typecheck job in the sub-invocation. Now the typecheck
module interface job is correctly setup to avoid diagnostics about
unsupported file system error.
Use a different context hash for modules built from caching using CAS
vs. normal swift modules. They should not be mixed since those cannot be
loaded as a dependencies for a module which is setup to build with a
different method.
rdar://122814823
