To avoid the crash of ModuleAnalyzer from invalid type comments, this
start to retry parsing without type_comments=False when `ast.parse()`
raises SyntaxError.

.. note::

   $ find sphinx tests LICENSE doc/conf.py -type f -exec sed -i '' -e 's/2007\-20../2007-2021/' {} \;
   $ git co sphinx/locale/**/*.js sphinx/templates/epub3/mimetype

Keep imports alphabetically sorted and their order homogeneous across
Python source files.

The isort project has more feature and is more active than the
flake8-import-order plugin.

Most issues caught were simply import ordering from the same module.
Where imports were purposefully placed out of order, tag with
isort:skip.

Developers can write number literals in several ways. For example,
decimal (1234), hexadecimal (0x1234), octal decimal (0o1234) and so on.
But, AST module don't mind how the numbers written in the code. As a
result, ast.unparse() could not reproduce the original form of number
literals.

This allows to construct number literals as possible using original
source code.

Note: This is only available in Python 3.8+.

This implements tuple literal support to sphinx.pycode.ast.unparse().

This will make it easier to remove them all at once in future

This should make it possible to reuse the same visitor to generate RST code.