importlib.abc.FileLoader.load_module()/get_filename() and
importlib.machinery.ExtensionFileLoader.load_module() have their
single argument be optional as the loader's constructor has all the
ncessary information.

This allows for the deprecation of
imp.load_source()/load_compile()/load_package().

importlib.machinery that provide the suffix details for import.
The attributes were not put on imp so as to compartmentalize
everything importlib needs for setting up imports in
importlib.machinery.

This also led to an indirect deprecation of inspect.getmoduleinfo() as
it directly returned imp.get_suffix's returned tuple which no longer
makes sense.

import machinery is no longer implicit.

support chflag operations.  (Patch by Hynek Schlawack)

support chflag operations.  (Patch by Hynek Schlawack)

Patch by Hynek Schlawack.

Patch by Hynek Schlawack.

In Python 3.2 and earlier, Process.join() and Connection.poll()
treated negative timeouts as zero timeouts.  Earlier versions from
the 3.3 line of development treat them as infinite timeouts.

The patch reverts to the old behaviour.

Optimize also PyUnicode_Format(): call unicode_writer_prepare() only once
per argument.

explicitly set UnsupportedOperation's module rather than relying on incorrect globals on startup (closes #14745)