[Dispatch] Don't crash when comparing DispatchWallTimes with <

Author: lilyball

stdlib/public/SDK/Dispatch/Time.swift

@@ -74,7 +74,7 @@ public struct DispatchWallTime : Comparable {
 
 public func <(a: DispatchWallTime, b: DispatchWallTime) -> Bool {
 	if a.rawValue == ~0 || b.rawValue == ~0 { return false }
-	return -Int64(a.rawValue) < -Int64(b.rawValue)
+	return -Int64(bitPattern: a.rawValue) < -Int64(bitPattern: b.rawValue)
 }
 
 public func ==(a: DispatchWallTime, b: DispatchWallTime) -> Bool {

test/stdlib/Dispatch.swift

@@ -85,3 +85,19 @@ DispatchAPI.test("dispatch_data_t deallocator") {
 		expectEqual(1, t)
 	}
 }
+
+DispatchAPI.test("DispatchTime comparisons") {
+    do {
+        let now = DispatchTime.now()
+        checkComparable([now, now + .milliseconds(1)], oracle: {
+            return $0 < $1 ? .lt : $0 == $1 ? .eq : .gt
+        })
+    }
+
+    do {
+        let now = DispatchWallTime.now()
+        checkComparable([now, now + .milliseconds(1)], oracle: {
+            return $0 < $1 ? .lt : $0 == $1 ? .eq : .gt
+        })
+    }
+}