pub fn specialize_stmts_with_state<'a>(
stmts: Vec<Stmt<'a>>,
expr_arena: &'a Arena<Expr<'a>>,
stmt_arena: &'a Arena<Stmt<'a>>,
interner: &mut Interner,
persistent_variant_count: &mut HashMap<Symbol, usize>,
bta_cache: Option<&BtaCache>,
) -> (Vec<Stmt<'a>>, usize)