Fix some compilation warnings and expose tracker names. (#376)

* Fix asyncsync compilation warnings.

* Fix tracker names should be public.

chronos/asyncsync.nim

@@ -154,7 +154,10 @@ proc wakeUpFirst(lock: AsyncLock): bool {.inline.} =
       res = true
       break
   if i > 0:
-    lock.waiters.delete(0, i - 1)
+    when compiles(lock.waiters.delete(0 .. (i - 1))):
+      lock.waiters.delete(0 .. (i - 1))
+    else:
+      lock.waiters.delete(0, i - 1)
   res
 
 proc checkAll(lock: AsyncLock): bool {.inline.} =
@@ -272,7 +275,10 @@ proc wakeupNext(waiters: var seq[Future[void]]) {.inline.} =
       break
 
   if i > 0:
-    waiters.delete(0, i - 1)
+    when compiles(waiters.delete(0 .. (i - 1))):
+      waiters.delete(0 .. (i - 1))
+    else:
+      waiters.delete(0, i - 1)
 
 proc full*[T](aq: AsyncQueue[T]): bool {.inline.} =
   ## Return ``true`` if there are ``maxsize`` items in the queue.

chronos/transports/datagram.nim

@@ -61,7 +61,7 @@ type
     closed*: int64
 
 const
-  DgramTransportTrackerName = "datagram.transport"
+  DgramTransportTrackerName* = "datagram.transport"
 
 proc remoteAddress*(transp: DatagramTransport): TransportAddress {.
     raises: [Defect, TransportOsError].} =

chronos/transports/stream.nim

@@ -71,8 +71,8 @@ type
     gcsafe, raises: [Defect].}
 
 const
-  StreamTransportTrackerName = "stream.transport"
-  StreamServerTrackerName = "stream.server"
+  StreamTransportTrackerName* = "stream.transport"
+  StreamServerTrackerName* = "stream.server"
 
 when defined(windows):
   type