Better abstract for associatedtype AsyncIterator

Author: Chris Adamson

stdlib/public/Concurrency/AsyncSequence.swift

@@ -74,7 +74,8 @@ import Swift
 @available(SwiftStdlib 5.5, *)
 @rethrows
 public protocol AsyncSequence {
-  /// The type of asynchronous iterator produced by this asynchronous sequence.
+  /// The type of asynchronous iterator that produces elements of this
+  /// asynchronous sequence.
   associatedtype AsyncIterator: AsyncIteratorProtocol where AsyncIterator.Element == Element
   /// The type of element produced by this asynchronous sequence.
   associatedtype Element