Revert "Enumerator should use a non-blocking fiber. (#10478)" (#10480)

This reverts commit dfa0897de8.

This commit accidentally included some change in `parse.h`. Reverting
and re-applying the relevant changes.

cont.c

@@ -2382,7 +2382,7 @@ rb_fiber_initialize(int argc, VALUE* argv, VALUE self)
 VALUE
 rb_fiber_new_storage(rb_block_call_func_t func, VALUE obj, VALUE storage)
 {
-    return fiber_initialize(fiber_alloc(rb_cFiber), rb_proc_new(func, obj), rb_fiber_pool_default(Qnil), 0, storage);
+    return fiber_initialize(fiber_alloc(rb_cFiber), rb_proc_new(func, obj), rb_fiber_pool_default(Qnil), 1, storage);
 }
 
 VALUE

internal/parse.h

@@ -68,7 +68,6 @@ rb_parser_string_t *rb_str_to_parser_string(rb_parser_t *p, VALUE str);
 void rb_parser_warn_duplicate_keys(struct parser_params *p, NODE *hash);
 int rb_parser_dvar_defined_ref(struct parser_params*, ID, ID**);
 ID rb_parser_internal_id(struct parser_params*);
-VALUE rb_parser_node_case_when_optimizable_literal(struct parser_params *p, const NODE *const node);
 int rb_parser_reg_fragment_check(struct parser_params*, rb_parser_string_t*, int);
 int rb_reg_named_capture_assign_iter_impl(struct parser_params *p, const char *s, long len, rb_encoding *enc, NODE **succ_block, const rb_code_location_t *loc);
 int rb_parser_local_defined(struct parser_params *p, ID id, const struct rb_iseq_struct *iseq);

test/fiber/test_enumerator.rb

@@ -42,12 +42,4 @@ class TestFiberEnumerator < Test::Unit::TestCase
     assert_predicate(i, :closed?)
     assert_predicate(o, :closed?)
   end
-
-  def enumerator_fiber_is_nonblocking
-    enumerator = Enumerator.new do |yielder|
-      yielder << Fiber.current.blocking?
-    end
-
-    assert_equal(false, enumerator.next)
-  end
 end