Clang: Fix warnings about unused members

Remove the unused members and remove also
ClangAssistProposalModel::[m_]replaceDotForArrow, which is a needled
indirection.

Change-Id: If6e0f65678b05fabd5fa16823a7a4c634b9fbdef
Reviewed-by: Marco Bubke <marco.bubke@theqtcompany.com>

src/plugins/clangcodemodel/clangassistproposalmodel.cpp

@@ -39,13 +39,6 @@
 namespace ClangCodeModel {
 namespace Internal {
 
-bool ClangAssistProposalModel::replaceDotForArrow(TextEditor::IAssistProposalModel *model)
-{
-    auto clangAssistProposalModel = static_cast<ClangAssistProposalModel*>(model);
-
-    return clangAssistProposalModel->m_replaceDotForArrow;
-}
-
 bool ClangAssistProposalModel::isSortable(const QString &/*prefix*/) const
 {
     return true;