Async overloading in protocol implementation fails

Number:rdar://FB9595388 Date Originated:3/9/2021
Status:Open Resolved:
Product:Swift Compiler Product Version:Apple Swift version 5.3.1 (swiftlang-1200.0.41 clang-1200.0.32.8)
Classification: Reproducible:yes
Amendment is incomplete.
Compilation fails, when class trying to satisfy protocol requirement with both sync and async method or just async method implementation.

protocol TestProtocol {
    func read() // Compilation also fails if TestProtocol contains only async version
    func read() async

// Note: everything compiles and resolves correctly when TestClass does not implement TestProtocol 
class TestClass: TestProtocol {
    func read() {}
    func read() async {}

Throws several issues:
error: type 'TestClass' does not conform to protocol 'TestProtocol'
note: multiple matching functions named 'read()' with type '() async -> ()'


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