[SourceKit] Include operation kind in compile notifications

- Compile will start / did finish now includes the operation
  kind (perform sema or code complete).
- See also
  https://forums.swift.org/t/sourcekit-lsp-file-status-ux/35947

utils/gyb_sourcekit_support/UIDs.py

@@ -182,6 +182,7 @@ UID_KEYS = [
     KEY('CompletionCheckDependencyInterval',
         'key.completion_check_dependency_interval'),
     KEY('AnnotatedTypename', 'key.annotated.typename'),
+    KEY('CompileOperation', 'key.compileoperation'),
 ]