swift

4cb03c27 - [diagnose-unreachable] Constant fold simple switch_enum_addr to eliminate more unreachable code.

[diagnose-unreachable] Constant fold simple switch_enum_addr to eliminate more unreachable code. This patch comes out of my reading some generic code using .none in transparent functions to conditionally compile out code at -Onone. Sadly, before this the dead code in question wouldn't be compiled out unless the protocol was constrained to be a class protocol. I added a test that validates that this conditional compilation property can be relied on in -Onone code in both cases.