message: Add Debug to GcStrategy
  Summary: Came in handy when debugging some things.
diff: @@ -62,7 +62,7 @@ fn assert_equals<'v>(a: Value<'v>, b: Value<'v>) -> anyhow::Result<NoneType> {
  /// How often we garbage collection _should_ be transparent to the tests,
  /// so we run each test in three configurations.
  -#[derive(Clone, Copy, Dupe)]
  +#[derive(Clone, Copy, Dupe, Debug)]
  enum GcStrategy {
  Never, // Disable GC
  Auto, // Use the automatic heuristics (in practice, this does almost no GC)
  