Fix #9513 to remove relative imports from multiprocessing.

The test suite currently skips test_multiprocessing on Windows
because it fails on finding _multiprocessing in several
win32-specific blocks. Removing the relative import lets this
through and allows the test to run (and pass).

Lib/multiprocessing/connection.py

@@ -173,7 +173,7 @@ if sys.platform != 'win32':
 
 else:
 
-    from ._multiprocessing import win32
+    from _multiprocessing import win32
 
     def Pipe(duplex=True):
         '''

Lib/multiprocessing/forking.py

@@ -157,7 +157,7 @@ else:
     import time
 
     from pickle import dump, load, HIGHEST_PROTOCOL
-    from ._multiprocessing import win32, Connection, PipeConnection
+    from _multiprocessing import win32, Connection, PipeConnection
     from .util import Finalize
 
     def dump(obj, file, protocol=None):

Lib/multiprocessing/heap.py

@@ -26,7 +26,7 @@ __all__ = ['BufferWrapper']
 
 if sys.platform == 'win32':
 
-    from ._multiprocessing import win32
+    from _multiprocessing import win32
 
     class Arena(object):
 

Lib/multiprocessing/reduction.py

@@ -34,7 +34,7 @@ if not(sys.platform == 'win32' or hasattr(_multiprocessing, 'recvfd')):
 
 if sys.platform == 'win32':
     import _subprocess
-    from ._multiprocessing import win32
+    from _multiprocessing import win32
 
     def send_handle(conn, handle, destination_pid):
         process_handle = win32.OpenProcess(