Proposal to remove Python 2 support

[Paul Koning]

> On Sep 15, 2020, at 4:46 PM, Tom Tromey <tom@tromey.com> wrote:
> 
> Hi.  Python 2 officially reached its sunset date this year:
> 
>    https://www.python.org/doc/sunset-python-2/
> 
> I think gdb should follow suit starting in gdb 11 -- that is, my
> proposal is to keep Python 2 support for the upcoming gdb 10 release,
> but remove said support from git master.
> 
> In the short term this would amount to some relatively minor code
> cleanups.

That makes sense to me.

> In the longer term, my preferred approach to handling inferior control
> from Python is to base it on async/await, which IIUC is only available
> in Python 3.  So, this would be an enabling step.

"await" appears in Python 3.5.  Do you want to drop support for 3.4 and earlier?  I guess they are no longer supported so that is arguably a valid thing to do, but I wonder how many packaged OS releases still come with versions that old.

	paul