CppEditor: Fix semantic highlighting when zooming

...for the not visible documents.

First reset the extra additional formats, then set the new ones, not the
other way around.

Task-number: QTCREATORBUG-14579
Change-Id: Iae465bd9a7bb0a397fd4917df45955713aaf87c5
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: David Schulz <david.schulz@theqtcompany.com>

src/plugins/cppeditor/cppeditordocument.cpp

@@ -169,6 +169,7 @@ void CppEditorDocument::applyFontSettings()
         }
     }
     TextDocument::applyFontSettings(); // rehighlights and updates additional formats
+    m_processor->semanticRehighlight();
 }
 
 void CppEditorDocument::invalidateFormatterCache()