Clang: Add UpdateTranslationUnitsForEditorMessage

If an editor is changing all translation units independent of their project
part they must be updated too. So we introduce a new message to update all
translation units with the same file path.

Change-Id: I70d0ea2bbca9fa880111ff7219573e54f3277026
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

src/libs/clangbackendipc/ipcclientinterface.h

@@ -37,6 +37,7 @@ namespace ClangBackEnd {
 
 class IpcServerInterface;
 class RegisterTranslationUnitForEditorMessage;
+class UpdateTranslationUnitsForEditorMessage;
 class RegisterProjectPartsForEditorMessage;
 class UnregisterTranslationUnitsForEditorMessage;
 class UnregisterProjectPartsForEditorMessage;