Clang: Use the clang indexer for indexing

It is not removing so much code but will makes somethings easier in the
future. We added the SymbolType::Definition too.

Change-Id: I4e106b8518e6bfed0c6a4aa6be61c4a5fe5f8bef
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/tools/clangrefactoringbackend/source/sourcelocationentry.h

@@ -38,9 +38,11 @@ namespace ClangBackEnd {
 
 enum class SymbolType
 {
+    None = 0,
     Declaration,
     DeclarationReference,
-    MacroDefinition,
+    Definition,
+    MacroDefinition = 1024,
     MacroUsage,
     MacroUndefinition
 };