swift

bf7eea08 - [Function builders] Infer function builder from a protocol requirement.

[Function builders] Infer function builder from a protocol requirement. Allow a protocol requirement for a function or property to declare a function builder. A witness to such a protocol requirement will infer that function builder when all of the following are two: * The witness does not explicitly adopt a function builder * The witness is declared within the same context that conforms to the protocol requirement (e.g., same extension or primary type declaration) * The witness's body does not contain a "return" statement (since those disable the function builder transform).