High Sierra Beta 5 Display Problems

[Bob Halley]

Yesterday I updated from macOS High Sierra beta 4 to beta 5, and now the Emacs 
display is oddly broken.  It's almost entirely black and white.  The mode line 
and fringes are solid black, including the text on the mode line!  Almost all 
font locking has stopped.  There is a little color still, e.g. selected text is 
highlighted reasonably.  All controls on customize screens are also 
black-on-black.  I didn't change anything on the emacs side, so I presume this 
is some interaction due to changes in macOS libraries.  I have no idea if emacs 
is doing something in a deprecated way, or if something got broken on High 
Sierra.

My build (from master) wasn't very old, but I rebuilt with the latest 
(846870e508021ee8d1099280b3f40fe108a34bf0) and it's still broken.

I am happy to help debug this given guidance about where to look or what to do. 
 I'm also happy to test patches.

Thanks in advance,

/Bob