add binary flag for core library desugaring and gate existing configuration flags by it.
RELNOTES: None.

PiperOrigin-RevId: 187075897
GitOrigin-RevId: cc090ed9b8544deea7a7c5cab17b263926e8c48b
Change-Id: I43a2d49e45095b23fc2c1249d1d3a97274e5b089
2 files changed
tree: 5908c5e95e3442f419e799c76d2addf2f159940f
  1. java/
  2. test/