[NFC] Update api-digester concurrency test.

(cherry picked from commit 7f5e47e)

Author: hborla

test/api-digester/stability-concurrency-abi.test

@@ -91,6 +91,9 @@ Func withCheckedThrowingContinuation(function:_:) has parameter 1 type change fr
 Func withCheckedContinuation(function:_:) has been renamed to Func withCheckedContinuation(isolation:function:_:)
 Func withCheckedContinuation(function:_:) has mangled name changing from '_Concurrency.withCheckedContinuation<A>(function: Swift.String, _: (Swift.CheckedContinuation<A, Swift.Never>) -> ()) async -> A' to '_Concurrency.withCheckedContinuation<A>(isolation: isolated Swift.Optional<Swift.Actor>, function: Swift.String, _: (Swift.CheckedContinuation<A, Swift.Never>) -> ()) async -> A'
 
+// AsyncStream.init(unfolding:onCancel:) uses @_silgen_name to preserve mangling after adding @preconcurrency.
+Constructor AsyncStream.init(unfolding:onCancel:) has mangled name changing from 'Swift.AsyncStream.init(unfolding: () async -> Swift.Optional<A>, onCancel: Swift.Optional<@Sendable () -> ()>) -> Swift.AsyncStream<A>' to 'Swift.AsyncStream.init(unfolding: () async -> Swift.Optional<A>, onCancel: Swift.Optional<() -> ()>) -> Swift.AsyncStream<A>'
+
 // SerialExecutor gained `enqueue(_: __owned Job)`, protocol requirements got default implementations
 Func SerialExecutor.enqueue(_:) has been added as a protocol requirement