Source changes for compilation

These are the commits from
https://github.com/ahgamut/cpython/tree/cosmo_py36 squashed for
simplicity.

Also included is the pyconfig.h used for compilation. The pyconfig.h has
to be changed manually in case Cosmopolitan gets new features.

third_party/python/Lib/_threading_local.py

@@ -143,15 +143,17 @@ __all__ = ["local"]
 # then, so problems introduced by fiddling the order of imports here won't
 # manifest.
 
+
 class _localimpl:
     """A class managing thread-local dicts"""
-    __slots__ = 'key', 'dicts', 'localargs', 'locallock', '__weakref__'
+
+    __slots__ = "key", "dicts", "localargs", "locallock", "__weakref__"
 
     def __init__(self):
         # The key used in the Thread objects' attribute dicts.
         # We keep it a string for speed but make it unlikely to clash with
         # a "real" attribute.
-        self.key = '_threading_local._localimpl.' + str(id(self))
+        self.key = "_threading_local._localimpl." + str(id(self))
         # { id(Thread) -> (ref(Thread), thread-local dict) }
         self.dicts = {}
 
@@ -167,11 +169,13 @@ class _localimpl:
         key = self.key
         thread = current_thread()
         idt = id(thread)
+
         def local_deleted(_, key=key):
             # When the localimpl is deleted, remove the thread attribute.
             thread = wrthread()
             if thread is not None:
                 del thread.__dict__[key]
+
         def thread_deleted(_, idt=idt):
             # When the thread is deleted, remove the local dict.
             # Note that this is suboptimal if the thread object gets
@@ -180,6 +184,7 @@ class _localimpl:
             local = wrlocal()
             if local is not None:
                 dct = local.dicts.pop(idt)
+
         wrlocal = ref(self, local_deleted)
         wrthread = ref(thread, thread_deleted)
         thread.__dict__[key] = wrlocal
@@ -189,7 +194,7 @@ class _localimpl:
 
 @contextmanager
 def _patch(self):
-    impl = object.__getattribute__(self, '_local__impl')
+    impl = object.__getattribute__(self, "_local__impl")
     try:
         dct = impl.get_dict()
     except KeyError:
@@ -197,12 +202,20 @@ def _patch(self):
         args, kw = impl.localargs
         self.__init__(*args, **kw)
     with impl.locallock:
-        object.__setattr__(self, '__dict__', dct)
+        object.__setattr__(self, "__dict__", dct)
         yield
 
 
+class DummyList(list):
+    def pop(self, index=-1):
+        try:
+            return super.pop(index)
+        except IndexError as e:
+            return None
+
+
 class local:
-    __slots__ = '_local__impl', '__dict__'
+    __slots__ = "_local__impl", "__dict__"
 
     def __new__(cls, *args, **kw):
         if (args or kw) and (cls.__init__ is object.__init__):
@@ -211,11 +224,12 @@ class local:
         impl = _localimpl()
         impl.localargs = (args, kw)
         impl.locallock = RLock()
-        object.__setattr__(self, '_local__impl', impl)
+        stack = DummyList()
+        object.__setattr__(self, "_local__impl", impl)
         # We need to create the thread dict in anticipation of
         # __init__ being called, to make sure we don't call it
         # again ourselves.
-        impl.create_dict()
+        impl.create_dict()["stack"] = stack
         return self
 
     def __getattribute__(self, name):
@@ -223,18 +237,18 @@ class local:
             return object.__getattribute__(self, name)
 
     def __setattr__(self, name, value):
-        if name == '__dict__':
+        if name == "__dict__":
             raise AttributeError(
-                "%r object attribute '__dict__' is read-only"
-                % self.__class__.__name__)
+                "%r object attribute '__dict__' is read-only" % self.__class__.__name__
+            )
         with _patch(self):
             return object.__setattr__(self, name, value)
 
     def __delattr__(self, name):
-        if name == '__dict__':
+        if name == "__dict__":
             raise AttributeError(
-                "%r object attribute '__dict__' is read-only"
-                % self.__class__.__name__)
+                "%r object attribute '__dict__' is read-only" % self.__class__.__name__
+            )
         with _patch(self):
             return object.__delattr__(self, name)