bpo-36373: Deprecate explicit loop in task and subprocess API (GH-16033)

diff --git a/Doc/library/asyncio-subprocess.rst b/Doc/library/asyncio-subprocess.rst
index 444fb63..bd92257 100644
--- a/Doc/library/asyncio-subprocess.rst
+++ b/Doc/library/asyncio-subprocess.rst
@@ -71,6 +71,10 @@
    See the documentation of :meth:`loop.subprocess_exec` for other
    parameters.
 
+   .. deprecated-removed:: 3.8 3.10
+
+      The *loop* parameter.
+
 .. coroutinefunction:: create_subprocess_shell(cmd, stdin=None, \
                           stdout=None, stderr=None, loop=None, \
                           limit=None, \*\*kwds)
@@ -95,6 +99,10 @@
    escape whitespace and special shell characters in strings that are going
    to be used to construct shell commands.
 
+   .. deprecated-removed:: 3.8 3.10
+
+      The *loop* parameter.
+
 .. note::
 
    The default asyncio event loop implementation on **Windows** does not