- Outlaw duplicate input files, fix driver, fix tests, and add test.
- Reflect that no buffer is present without a (possibly pseudo) named file.
- Reflect fact that every input has a (possible pseudo) name.
- Break up CompilerInstance::setup.
Don't bail on dups.
Encapsulate uses of the variables in FrontendInputs with intention-describing functions. Move some code that sets these variables into FrontendInputs and FrontendOptions classes.
Create new FrontendInputs class to encapsulate InputFilenames, InputBuffers and PrimaryInput, which were formerly in Frontend.
Includes one change in SwiftEditor.cpp to resolve a merge conflict.
This has the effect of propagating the search path to the clang importer as '-iframework'.
It doesn't affect whether a swift module is treated as system or not, this can be done as follow-up enhancement.
I am going to use this in bug reducer for debugging runtime crashes. I just
found the branch and cleaned it up, so I fugred I would commit it sooner rather
than after I lost the branch again.
