[cmake-developers] Drop support for older Xcode versions?

[Tim Blechmann]

>> Given Apple's encouragement of developers to always update...
> 
> They certainly do, as Eric described.  However, just like everyone
> else, Apple often ships regressions in Xcode and it's sometimes vital
> to be able to use older versions.  Similarly, if you want to deploy
> an app to an older OS, it's very useful to be able to build-run-debug
> on that OS, and since the newest Xcodes only run on the newest OSes,
> one needs an older Xcode to test/debug on older OSes.

if a project relies on an old xcode version, does it need to use the
most up-to-date cmake? also, there are always make/ninja generators ...