Block continuations as close as possible to try block

This reduces the risk of an exception by-passing the finally block

Author: gilles-duboscq

espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/nodes/NativeMethodNode.java

@@ -102,11 +102,11 @@ private Object[] preprocessArgs(JniEnv env, Object[] args) {
 
     @Override
     public Object execute(VirtualFrame frame) {
-        var tls = getContext().getLanguage().getThreadLocalState();
-        tls.blockContinuationSuspension();   // Can't unwind through native frames.
         final JniEnv env = getContext().getJNI();
         int nativeFrame = env.getHandles().pushFrame();
         NATIVE_METHOD_CALLS.inc();
+        var tls = getContext().getLanguage().getThreadLocalState();
+        tls.blockContinuationSuspension();   // Can't unwind through native frames.
         try {
             Object[] nativeArgs = preprocessArgs(env, frame.getArguments());
             Object result = executeNative.execute(boundNative, nativeArgs);