gh-84461: Fix ctypes and test_ctypes on Emscripten (#94142)

- c_longlong and c_longdouble need experimental WASM bigint.
- Skip tests that need threading
- Define ``CTYPES_MAX_ARGCOUNT`` for Emscripten. libffi-emscripten 2022-06-23 supports up to 1000 args.

Lib/test/test_code.py

@@ -141,6 +141,7 @@ from test.support import (cpython_only,
                           check_impl_detail, requires_debug_ranges,
                           gc_collect)
 from test.support.script_helper import assert_python_ok
+from test.support import threading_helper
 from opcode import opmap
 COPY_FREE_VARS = opmap['COPY_FREE_VARS']
 
@@ -723,6 +724,7 @@ if check_impl_detail(cpython=True) and ctypes is not None:
             self.assertEqual(extra.value, 300)
             del f
 
+        @threading_helper.requires_working_threading()
         def test_free_different_thread(self):
             # Freeing a code object on a different thread then
             # where the co_extra was set should be safe.