Don't grab the threads stacktrace when dumping same thread

For some reason, this doesn't always seem to capture all states of shutdown,
either the logger is just being fun, or, potentially, the thread is already
marked as dead when we're getting called so the trace is not generated through
the method on Thread

Spigot-Server-Patches/0676-misc-debugging-dumps.patch

@@ -6,10 +6,10 @@ Subject: [PATCH] misc debugging dumps
 
 diff --git a/src/main/java/io/papermc/paper/util/TraceUtil.java b/src/main/java/io/papermc/paper/util/TraceUtil.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..d5e5c6153675855bb8798b11d905b5f2d6ea158e
+index 0000000000000000000000000000000000000000..2d5494d2813b773e60ddba6790b750a9a08f21f8
 --- /dev/null
 +++ b/src/main/java/io/papermc/paper/util/TraceUtil.java
-@@ -0,0 +1,14 @@
+@@ -0,0 +1,18 @@
 +package io.papermc.paper.util;
 +
 +import org.bukkit.Bukkit;
@@ -23,9 +23,13 @@ index 0000000000000000000000000000000000000000..d5e5c6153675855bb8798b11d905b5f2
 +            Bukkit.getLogger().warning("\tat " + traceElement);
 +        }
 +    }
++
++    public static void dumpTraceForThread(String reason) {
++        new Throwable(reason).printStackTrace();
++    }
 +}
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index ccf2d0b090f0c360dfc7886bb0726e099acec42c..ccac3589820f244f36dac310d08091f218d5935e 100644
+index ccf2d0b090f0c360dfc7886bb0726e099acec42c..d6ca2ac9a5047b8d6840c8b4985ab75f35bea919 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
 @@ -15,6 +15,7 @@ import io.netty.buffer.ByteBuf;
@@ -48,7 +52,7 @@ index ccf2d0b090f0c360dfc7886bb0726e099acec42c..ccac3589820f244f36dac310d08091f2
              if (hasStopped) return;
              hasStopped = true;
          }
-+        if (!hasLoggedStop && isDebugging()) TraceUtil.dumpTraceForThread(this.getThread(), "Server stopped"); // Paper
++        if (!hasLoggedStop && isDebugging()) TraceUtil.dumpTraceForThread("Server stopped"); // Paper
          // Paper start - kill main thread, and kill it hard
          shutdownThread = Thread.currentThread();
          org.spigotmc.WatchdogThread.doStop(); // Paper
@@ -57,7 +61,7 @@ index ccf2d0b090f0c360dfc7886bb0726e099acec42c..ccac3589820f244f36dac310d08091f2
          this.isRunning = false;
          this.isRestarting = isRestarting;
 +        this.hasLoggedStop = true; // Paper
-+        if (isDebugging()) TraceUtil.dumpTraceForThread(this.getThread(), "Server stopped"); // Paper
++        if (isDebugging()) TraceUtil.dumpTraceForThread("Server stopped"); // Paper
          if (flag) {
              try {
                  this.serverThread.join();