NS runtime feature detection (was: Mac OS Sierra tab feature breaks C-x 5 2)

[Alan Third]

On Sat, Jul 22, 2017 at 12:22:30PM +0100, Alan Third wrote:
> Or perhaps we provide a flag that enables a universal binary build
> that doesn’t bother about hiding the warnings?

Attached is a first attempt at this in nsterm.m. I think I’ve got
everything, but there may be some new variables and things defined
that I’ve missed which will throw up errors in older macOS versions.

It seems ‘universal binary’ means something specific, so I went with a
different name.

Use:

    ./configure --with-ns --enable-macos-runtime-feature-detection

It will give a lot of deprecation and unknown method warnings, but
hopefully that’s all.

If you build normally there should be no (new) warnings or errors.
-- 
Alan Third

0001-Use-a-run-time-check-for-macOS-Sierra-tabbing-suppor.patch
Description: Text document