[jvm] Type.getClass() should return null for anons (fixes #8286)

std/jvm/_std/Type.hx

@@ -44,7 +44,7 @@ class Type {
 		if (isEnumValueClass(c)) {
 			return null;
 		}
-		if (c == jvm.DynamicObject.native()) {
+		if (c == jvm.DynamicObject.native() || Jvm.instanceof(o, jvm.DynamicObject)) {
 			return null;
 		}
 		return c.haxe();

tests/unit/src/unit/issues/Issue8286.hx

@@ -0,0 +1,7 @@
+package unit.issues;
+
+class Issue8286 extends unit.Test {
+	function test() {
+		eq(null, Type.getClass({a: 1}));
+	}
+}