Fixing SourceKit Structure

July 2017, swift:master

Part 1 - typealias

Typealias is missing from editoropen. Fix plan:

1. SyntaxModel.h - new SyntaxStructureKind.TypeAlias It’s OK to add to the middle of this enum because it does not escape the executable.
2. SwiftLangSupport.cpp - handle new kind in getUIDForSyntaxStructureKind(), map to existing KindDeclTypeAlias.
3. SyntaxModel.cpp - add another else to walkToDeclPre().
4. Fix up tests.

Along the way:

1. Discovered swift/tools/swift-ide-test/swift-ide-test.cpp another dependency on SyntaxWalker. Just added the handler, nothing special.
2. Need to decide what to put in BodyLength/Offset - go with nothing, like var f = 2.
3. Decided not to add associatedtype or anything else easy for this first PR, don’t overcomplicate things.

PR 11143

Should have added a test for swift-ide-test change.

Part 2 - everything else

Sit back + leave to Marcelo - LOL.