[Wisp] Get the correct _thread_stat in Coroutine

Summary: We get the wrong _thread_stat in wisp, which will make PerfCounter not precise and may cause an assert error as well.

Test Plan: test/jdk/com/alibaba/wisp/io/TestDatagramSocket.java with -XX:+UseWispMonitor, and other tests

Reviewers: shiyue.xw, lei.yul, sanhong.lsh

Issue: https://aone.alibaba-inc.com/task/29031438

CR: https://code.aone.alibaba-inc.com/xcode/jdk11/codereview/3219099

src/hotspot/share/runtime/thread.cpp

@@ -3288,6 +3288,10 @@ void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
  Threads::add(this);
 }
 
+ThreadStatistics* JavaThread::get_thread_stat() const {
+ return UseWispMonitor ? WispThread::current(const_cast<JavaThread*>(this))->_thread_stat : _thread_stat;
+}
+
 oop JavaThread::current_park_blocker() {
  // Support for JSR-166 locks
  oop thread_oop = threadObj();

src/hotspot/share/runtime/thread.hpp

@@ -2027,7 +2027,7 @@ class JavaThread: public Thread {
  ThreadStatistics *_thread_stat;
 
  public:
- ThreadStatistics* get_thread_stat() const { return _thread_stat; }
+ ThreadStatistics* get_thread_stat() const;
 
  // Return a blocker object for which this thread is blocked parking.
  oop current_park_blocker();

test/jdk/com/alibaba/wisp/io/TestDatagramSocket.java

@@ -3,7 +3,7 @@
  * @library /lib/testlibrary
  * @summary Test WispEngine's DatagramSocket, InitialDirContext use dup socket to query dns.
  * @modules java.base/jdk.internal.misc
- * @run main/othervm -XX:+EnableCoroutine -Dcom.alibaba.wisp.transparentWispSwitch=true TestDatagramSocket
+ * @run main/othervm -XX:+EnableCoroutine -XX:+UseWispMonitor -Dcom.alibaba.wisp.transparentWispSwitch=true TestDatagramSocket
 */