Need to implement support of virtual threds in JVMTI StopThread.
The spec update is:

diff --git a/src/hotspot/share/prims/jvmti.xml b/src/hotspot/share/prims/jvmti.xml
index 456876fbcb9..da93a5fcb68 100644
--- a/src/hotspot/share/prims/jvmti.xml
+++ b/src/hotspot/share/prims/jvmti.xml
@@ -1892,7 +1892,7 @@ jvmtiEnv *jvmti;
     <function id="StopThread" num="7">
       <synopsis>Stop Thread</synopsis>
       <description>
- Send the specified asynchronous exception to the specified platform thread.
+ Send the specified asynchronous exception to the specified thread.
       </description>
       <origin>jvmdi</origin>
       <capabilities>
@@ -1903,8 +1903,10 @@ jvmtiEnv *jvmti;
           <jthread impl="noconvert"/>
             <description>
               The thread to stop.
- The <code>thread</code> may not be a virtual thread. Otherwise, the error code
- <errorlink id="JVMTI_ERROR_UNSUPPORTED_OPERATION"></errorlink> will be returned.
+ The <functionlink id="StopThread"></functionlink> function may be used to send
+ an asynchronous exception to a virtual thread when it is suspended at an event.
+ An implementation may support sending an asynchronous exception to a suspended
+ virtual thread in other cases.
              </description>
         </param>
         <param id="exception">
@@ -1915,8 +1917,12 @@ jvmtiEnv *jvmti;
         </param>
       </parameters>
       <errors>
- <error id="JVMTI_ERROR_UNSUPPORTED_OPERATION">
- <paramlink id="thread"/> is a virtual thread.
+ <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
+ Thread is a virtual thread and was not suspended and was not the current thread.
+ </error>
+ <error id="JVMTI_ERROR_OPAQUE_FRAME">
+ The thread is a suspended virtual thread and the implementation was unable
+ to throw an asynchronous exception from this frame.
         </error>
       </errors>
     </function>
@@ -11974,7 +11980,8 @@ myInit() {
       There are no Java programming language or JNI stack frames at the specified depth.
     </errorid>
     <errorid id="JVMTI_ERROR_OPAQUE_FRAME" num="32">
- Information about the frame is not available (e.g. for native frames).
+ Information about the frame is not available (e.g. for native frames),
+ or the frame is not suitable for the requested operation.
     </errorid>
     <errorid id="JVMTI_ERROR_DUPLICATE" num="40">
       Item already set.