Avoid NPE in hasUnresolvableGenerics()

Issue: SPR-11034

spring-core/src/main/java/org/springframework/core/ResolvableType.java

@@ -365,6 +365,7 @@ public final class ResolvableType implements Serializable {
 			}
 		}
 		Class<?> resolved = resolve();
+		if (resolved != null) {
 			Type[] ifcs = resolved.getGenericInterfaces();
 			for (Type ifc : ifcs) {
 				if (ifc instanceof Class) {
@@ -376,6 +377,7 @@ public final class ResolvableType implements Serializable {
 			if (resolved.getGenericSuperclass() != null) {
 				return getSuperType().hasUnresolvableGenerics();
 			}
+		}
 		return false;
 	}