swift

c3964c79 - [Concurrency] Fix too eager early return in checkIsolation mode detecting

[Concurrency] Fix too eager early return in checkIsolation mode detecting If we have the ability to check env variables, and there was no env variable set we aggressively bailed out of the function's logic, without setting the executor mode at all. This prevented the dynamic modes from working in real (non testing) scenarios. Resolves rdar://127400013