Sync typeshed (#5327)

In preparation for the release.

This also fixes minor related errors in self-check.

Author: ilevkivskyi

mypy/dmypy_server.py

@@ -39,6 +39,8 @@ def daemonize(func: Callable[[], None], log_file: Optional[str] = None) -> int:
     subprocess killed by signal.
     """
     # See https://stackoverflow.com/questions/473620/how-do-you-create-a-daemon-in-python
+    if sys.platform == 'win32':
+        raise ValueError('Mypy daemon is not supported on Windows yet')
     sys.stdout.flush()
     sys.stderr.flush()
     pid = os.fork()

mypy/test/testsamples.py

@@ -44,7 +44,7 @@ def test_stdlibsamples(self) -> None:
                 modules.append(f)
         if modules:
             # TODO: Remove need for --no-strict-optional
-            run_mypy(['--no-strict-optional'] + modules)
+            run_mypy(['--no-strict-optional', '--platform=linux'] + modules)
 
 
 def find_files(base: str, prefix: str = '', suffix: str = '') -> List[str]:

typeshed

@@ -130,7 +130,7 @@ def __init__(self, limit: int = 0, *, verbosity: int = 0, xfail: List[str] = [],
         self.current = {}  # type: Dict[int, Tuple[int, LazySubprocess]]
         if limit == 0:
             try:
-                sched_getaffinity = os.sched_getaffinity
+                sched_getaffinity = os.sched_getaffinity  # type: ignore
             except AttributeError:
                 # no support for affinity on OSX/Windows
                 limit = cpu_count()