JVMTI Spec: async-signal safe method to get the state of the current thread

A new API is requested by the Performance Analyzer to provide information about
the state of the current thread (from which a call is made). Possible states
of interest are:
NON_JAVA - a call is made on a non-Java thread;
JCPU - JVM is executing a Java method
(either interpreted or compiled);
GC - the thread is in garbage collection state
(either blocked or executing GC related code);
HS - the thread is in HotSpot compilation state
(either waiting for dynamic compilation to
finish or executing related code);
JVM - other JVM overhead not immediately
related to byte code execution;
LOCK - the thread is locked on a Java monitor;
NATIVE - the thread is executing native code (JNI);

The state information can be made part of AsyncGetCallTrace result or
provided by a new API call, f.e. AsyncThreadState().


###@###.### 2002-11-04

Moved to java/profiling since this will be addressed by JSR-163.