Proxy doesn't work without module system initialization

[yuvaraj-anbarasan]

The following is the exception thrown by proxy tests, testBasicProxy and testAnnoProxy,

gov.nasa.jpf.vm.NoUncaughtExceptionsProperty
java.lang.InternalError: Proxy is not supported until module system is fully initialized
	at java.lang.reflect.Proxy$ProxyBuilder.<init>(Proxy.java:616)
	at java.lang.reflect.Proxy$ProxyBuilder.<init>(Proxy.java:635)
	at java.lang.reflect.Proxy.lambda$getProxyConstructor$0(Proxy.java:415)
	at java.lang.reflect.Proxy$0.apply
	at jdk.internal.loader.AbstractClassLoaderValue$Memoizer.get(AbstractClassLoaderValue.java:329)
	at jdk.internal.loader.AbstractClassLoaderValue.computeIfAbsent(AbstractClassLoaderValue.java:205)
	at java.lang.reflect.Proxy.getProxyConstructor(Proxy.java:413)
	at java.lang.reflect.Proxy.newProxyInstance(Proxy.java:1006)
	at gov.nasa.jpf.test.vm.reflection.ProxyTest.testAnnoProxy(ProxyTest.java:88)
	at java.lang.reflect.Method.invoke(gov.nasa.jpf.vm.JPF_java_lang_reflect_Method)
	at gov.nasa.jpf.util.test.TestJPF.runTestMethod(TestJPF.java:648)

#259

[quadhier]

Hi @cyrille-artho and @pparizek, Proxy has been supported since #356. Maybe we could close this issue now.