Grammar reifier forgets non-terminals if there exists a layout non-terminal with the same name.

[jurgenvinju]

Describe the bug

rascal>layout A = " "*;
ok
rascal>syntax A = "a" | "b" "b";
ok
rascal>#A
type[A]: type(
  sort("A"),
  (
    layouts("$default$"):choice(
      layouts("$default$"),
      {prod(
          layouts("$default$"),
          [],
          {})}),
    empty():choice(
      empty(),
      {prod(
          empty(),
          [],
          {})}),
    layouts("A"):choice(
      layouts("A"),
      {
        prod(
          layouts("A"),
          [lit("a")],
          {}),
        prod(
          layouts("A"),
          [
            lit("b"),
            layouts("A"),
            lit("b")
          ],
          {})
      })
  ))
rascal>

If we reify #A then the syntax sort is lost and all the productions for syntax A end up with layout A. The original rule for layout A seems to be lost completely. That's probably due to an update in the definitions map that overwrites the original value at key layouts("A").

• We might have to add a warning or error to the type-checker to prevent this situation from happening
• It's worth fixing the bug in the code of the parser generator that does the reification of the syntax definition into a grammar value.