Some editors use diagnostics from SourceKit to replace build issues. This causes issues if the diagnostics from SourceKit are formatted differently than the build issues. Make sure they are rendered the same way, removing most uses of `DiagnosticsEditorMode`.
To do so, always emit the `add stubs for conformance` note (which previously was only emitted in editor mode) and remove all `; add <something>` suffixes from notes that state which requirements are missing.
rdar://129283608
This commit changes fixit messages from a question/suggestion to an
imperative message for protocol conformances and switch-case. Addresses
https://github.com/apple/swift/issues/67510.
If the setter conflict occurs in a deserialized declaration, the parent
pattern binding can be NULL. Guard the fixit on the existence of the
pattern binding so
1) we don't crash
2) we don't try to emit a fixit in otherwise extremely broken code
rdar://56558082
