Dropping support for OSX 32 bit

[Nicholas Wilson]

So Apple has dropped support for 32 bit apps in the latest OS 
release (September last year).

Officially we support 10.9 (Mavericks) released October 2013. All 
supported versions run on 64bit processors, Apple support (I 
think?) 10.11 and newer (we should probably raise that to be in 
line but thats a different problem: see 
https://forum.dlang.org/thread/CAOC+-J-iZnpvEvFu5womjuy2H_ZiUzPytVDZfxoPuv1zYt173g@mail.gmail.com).

The newer c++ standard library support is disabled on the 32 bit 
configurations of the CI pipeline and is currently blocking 
https://github.com/dlang/dmd/pull/9143

Removal of support has been requested 
https://github.com/ldc-developers/ldc/issues/2959
and by many who have experienced the ~~joy~~ pain of dealing with 
CI failures related to OSX32.

1) Does anyone actually build for 32bit OSX?
2) Is everyone happy with accelerating EOL for D support of OSX32?

Please reply so we can get a representative sample.