mpv, ffmpeg seg fault in macOS catalina

[Chris Jones]

Hi,

> Workaround is to either blacklist the compiler which has this option 
> turned on by default (which is what Chris replied) or in fact use a flag 
> to disable this. But disabling this flag is not needed for non-broken 
> compilers, so it's probably better to just blacklist the compiler, and 
> the latest compiler with be automatically used again when the bug gets 
> fixed.

Currently I black list {clang > 1099}, so anything in current and future 
Xcode 11 versions. The (insider) claim was Xcode 11.2 'should' address 
this, but last I heard 11.2 beta 2 still had the problem, so time will tell.

Once the fixed clang version is known, the above blacklists can then be 
adjusted to make them non-open ended, but we need to know the fixed 
version first...

Chris