Member predicate TypeCase::getVariableDeclExpr

Gets the local variable declaration of this type case, if any. For example, the local variable declaration of the type case on line 3 is string s in

switch(p) {
  case int i:
  case string s when s.Length>0:
    break;
  case bool _:
    break;
  ...
}
LocalVariableDeclExpr getVariableDeclExpr()