Android 9.0.0 release 42
Make slang able to take target API level 27 and 28

  - Add enums corresponding O-MR1 and P.
  - Internally, treat them as N since no new APIs added.

Bug: 72969487
Test: mm
Test: llvm-rs-cc can take target api 27 and 28, and generated code works
on N emulator and ToT walleye.

Change-Id: I37979fe359aee117229182cdd198f5305dd22cd1
2 files changed