swift234

[SourceKit] Split SourceDocInfo tests into CursorInfo and RelatedIdents subdirectories

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).