Use new cython on Windows too.

appveyor.yml

@@ -131,7 +131,8 @@ install:
   # pip will build them from source using the MSVC compiler matching the
   # target Python version and architecture
   # Note that psutil won't build under PyPy on Windows.
-  - "%CMD_IN_ENV% pip install -U setuptools wheel cython greenlet cffi dnspython idna"
+  - "%CMD_IN_ENV% pip install -e git+https://github.com/cython/cython.git@63cd3bbb5eac22b92808eeb90b512359e3def20a#egg=cython"
+  - "%CMD_IN_ENV% pip install -U setuptools wheel greenlet cffi dnspython idna"
 
   - ps:
       if ("${env:PYTHON_ID}" -ne "pypy") {

setup.py

@@ -143,9 +143,13 @@ if PYPY:
     # As of PyPy 5.10, this builds, but won't import (missing _Py_ReprEnter)
     EXT_MODULES.remove(CORE)
 
+    # This uses PyWeakReference and doesn't compile on PyPy
+    EXT_MODULES.remove(IDENT)
+
     _to_cythonize.remove(LOCAL)
     _to_cythonize.remove(GREENLET)
     _to_cythonize.remove(SEMAPHORE)
+    _to_cythonize.remove(IDENT)
 
 for mod in _to_cythonize:
     EXT_MODULES.remove(mod)