Clang: Remove option for code completion

Completion should be faster and the test are still running.

Change-Id: If663e80ce349547b0948412e52b9bf4f76cbb011
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

src/tools/clangbackend/ipcsource/translationunit.cpp

@@ -163,8 +163,7 @@ void TranslationUnit::removeOutdatedTranslationUnit() const
 
 void TranslationUnit::createTranslationUnitIfNeeded() const
 {
-    const auto options = CXTranslationUnit_DetailedPreprocessingRecord
-            | CXTranslationUnit_CacheCompletionResults
+    const auto options = CXTranslationUnit_CacheCompletionResults
             | CXTranslationUnit_PrecompiledPreamble
             | CXTranslationUnit_SkipFunctionBodies;