[SE-0304] Rename Task.yield() to Task.suspend()

Author: DougGregor

stdlib/public/Concurrency/Task.swift

@@ -645,6 +645,8 @@ extension Task where Success == Never, Failure == Never {
   /// This is not a perfect cure for starvation;
   /// if the task is the highest-priority task in the system, it might go
   /// immediately back to executing.
+  ///
+  @available(*, deprecated, renamed: "suspend()")
   public static func yield() async {
     let currentTask = Builtin.getCurrentAsyncTask()
     let priority = getJobFlags(currentTask).priority ?? Task.currentPriority._downgradeUserInteractive
@@ -654,6 +656,11 @@ extension Task where Success == Never, Failure == Never {
       _enqueueJobGlobal(job)
     }
   }
+
+  @_alwaysEmitIntoClient
+  public static func suspend() async {
+    await yield()
+  }
 }
 
 // ==== UnsafeCurrentTask ------------------------------------------------------