All trace messages (usages of EVT_TRACE and EVT_TRIG_TRACE macros)
in JvmtiExport.cpp need to re-examined as many of of them are using
oops rather than Handles. If there are multiple environments enabled
then a GC can occur when in the agent's callback and objects may
when it gets to post the event for the next and subsequent environments.

Some examples :-

JvmtiExport::post_raw_breakpoint's use of 'method'
JvmtiExport::post_class_load's use of of 'klass'
JvmtiExport::post_class_prepare's use of 'klass'
JvmtiExport::post_method_entry's use of 'method'
JvmtiExport::post_method_exit's use of 'method'
JvmtiExport::post_single_step's use of 'method'
JvmtiExport::post_exception_throw's use of 'method' and 'exception'
JvmtiExport::notice_unwind_due_to_exception's use of 'method'
JvmtiExport::post_field_access's use of 'method'
:
:

###@###.### 2003-11-24