Initial description from Alan:
 “The SetLocalXXX functions may be used to set the value of a local variable in the topmost frame of a virtual thread suspended at a breakpoint or single step event. An implementation may support setting locals in other cases.”
 We want to re-visit this wording and/or require that the virtual thread be suspended.
 Also, the spec of all GetLocalXXX/SetLocalXXX should require the target thread be suspended or current even if the thread is non-virtual.

Updated description:
The implementation of SetLocalXXX for virtual threads has just been fixed with JDK-8286580 to follow the JVMTI spec.
However, it was identified that the GetLocalXXX/SetLocalXXX function should require suspending the target thread. All these functions have a stack depth parameter. There only way to ensure the execution state of target thread matches the stack depth expectations is to deal with current or suspended target thread. This needs a CSR and other compatibility checks.