Add timing on reconnecting

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/BotImpl.kt

@@ -24,6 +24,8 @@ import net.mamoe.mirai.network.closeAndJoin
 import net.mamoe.mirai.utils.*
 import net.mamoe.mirai.utils.internal.retryCatching
 import kotlin.coroutines.CoroutineContext
+import kotlin.time.ExperimentalTime
+import kotlin.time.measureTime
 
 /*
  * 泛型 N 不需要向外(接口)暴露.
@@ -86,6 +88,7 @@ abstract class BotImpl<N : BotNetworkHandler> constructor(
     @Throws(LoginFailedException::class) // only
     protected abstract suspend fun relogin(cause: Throwable?)
 
+    @OptIn(ExperimentalTime::class)
     @Suppress("unused")
     private val offlineListener: Listener<BotOfflineEvent> =
         this@BotImpl.subscribeAlways(concurrency = Listener.ConcurrencyKind.LOCKED) { event ->
@@ -103,6 +106,7 @@ abstract class BotImpl<N : BotNetworkHandler> constructor(
                     }
                     bot.logger.info { "Connection dropped by server or lost, retrying login" }
 
+                    val time = measureTime {
                         tailrec suspend fun reconnect() {
                             retryCatching<Unit>(configuration.reconnectionRetryTimes,
                                 except = LoginFailedException::class) { tryCount, _ ->
@@ -116,7 +120,6 @@ abstract class BotImpl<N : BotNetworkHandler> constructor(
                                     @OptIn(ThisApiMustBeUsedInWithConnectionLockBlock::class)
                                     relogin((event as? BotOfflineEvent.Dropped)?.cause)
                                 }
-                            logger.info { "Reconnected successfully" }
                                 BotReloginEvent(bot, (event as? BotOfflineEvent.Dropped)?.cause).broadcast()
                                 return
                             }.getOrElse {
@@ -132,9 +135,11 @@ abstract class BotImpl<N : BotNetworkHandler> constructor(
                             }
                             reconnect()
                         }
-
                         reconnect()
                     }
+
+                    logger.info { "Reconnected successfully in ${time.inMilliseconds} ms" }
+                }
                 is BotOfflineEvent.Active -> {
                     val msg = if (event.cause == null) {
                         ""