This allows building sourcekitd and swift-refactor with `SWIFT_BUILD_SWIFT_SYNTAX=NO`. In these builds, the `relatedidents` and `find-syntactic-rename-ranges` requests will always return an error.
Cursor info for a constructor would previously give the cursor info for
the containing type only. It now also adds cursor info for the
constructor itself in a "secondary_symbols" field.
Refactor `passCursorInfoForDecl` to use a single allocator rather than
keeping track of positions in a buffer and assigning everything at the
end of the function.
Refactor the various available refactoring gathering functions to take a
SmallVectorImpl and to not copy strings where they don't need to.
Resolves rdar://75385556
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).
