ClangSupport: Use simpler structures in some cases

The patch is mostly mechanical, but contains also a few spurious changes
from values references for some local variables, foreach -> ranged for
etc that I coulnd't resist.

Change-Id: I58f0bd972546895eb318607cbfbd7ac35caf3f23
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/plugins/cppeditor/cppeditorwidget.cpp

@@ -573,8 +573,8 @@ QList<QTextEdit::ExtraSelection> sourceLocationsToExtraSelections(
         QTextEdit::ExtraSelection selection;
 
         selection.cursor = selectAt(cppEditorWidget->textCursor(),
-                                    sourceLocation.line(),
-                                    sourceLocation.column(),
+                                    sourceLocation.line,
+                                    sourceLocation.column,
                                     selectionLength);
         selection.format = textCharFormat;