Added test for loading Foo<?> type from Java.

compiler/testData/loadJava/UnboundWildcard.kt

@@ -0,0 +1,7 @@
+package test
+
+public final class UnboundWildcard: Object() {
+    public final fun foo(): MyClass<*>? = throw UnsupportedOperationException()
+
+    public trait MyClass<T: CharSequence?>: Object
+}