The mangled name of the type is identical to those for debugger. These
mangled names allow us to reconstruct the type from AST and generate interface
specifically for that type.
Related rdar://27306890
Unless you're familiar with the way the swift source code is organized,
it's not clear what "SourceDocInfo" means, or how it is different from
DocSupport, etc. Move the tests into directories that are named based
on their request (note: we already had one test under CursorInfo, which
just made things even more confusing).
