Enter endless loop after V8::TerminateExecution call, fixes #135

The V8::TerminateExecution does *not* immediately terminate execution
as its name might suggest.  It just marks the given isolate as
"to terminate" and the execution thread checks - from time to time -
whether to terminate.  For v8 itself this is not problematic as
the call is thought to stop long-running scripts executed in the
browser context.

As v8js exposes this function to JavaScript with the exit() method,
this behaviour is confusing.  In order to stop code execution right
at the exit() call, v8js enters an endless loop and waits for v8
to terminate execution within it.

v8js_methods.cc

@@ -27,7 +27,21 @@ void v8js_commonjs_normalise_identifier(char *base, char *identifier, char *norm
 /* global.exit - terminate execution */
 V8JS_METHOD(exit) /* {{{ */
 {
-	v8::V8::TerminateExecution(info.GetIsolate());
+	v8::Isolate *isolate = info.GetIsolate();
+
+	/* Unfortunately just calling TerminateExecution on the isolate is not
+	 * enough, since v8 just marks the thread as "to be aborted" and doesn't
+	 * immediately do so.  Hence we enter an endless loop after signalling
+	 * termination, so we definitely don't execute JS code after the exit()
+	 * statement. */
+	v8::Locker locker(isolate);
+	v8::Isolate::Scope isolate_scope(isolate);
+	v8::HandleScope handle_scope(isolate);
+
+	v8::Local<v8::String> source = V8JS_STR("for(;;);");
+	v8::Local<v8::Script> script = v8::Script::Compile(source);
+	v8::V8::TerminateExecution(isolate);
+	script->Run();
 }
 /* }}} */