This is a patch for clang autocomplete feature.
It will collect values which -analyzer-checker takes, which is defined in
First, from ValuesCode class in Options.td, TableGen will generate C++
code in Options.inc. Options.inc will be included in DriverOptions.cpp, and
calls OptTable's addValues function. addValues function will add second
argument to Option's Values class. Values contains string like "foo,bar,.."
which is handed to Values class