Allow a MethodReference to be produced from a GeneratedMethod

This commit updates GeneratedMethod and its underlying infrastructure
to be able to produce a MethodReference. This simplifies the need when
such a reference needs to be created manually and reuses more of what
MethodReference has to offer.

See gh-29005

spring-aop/src/main/java/org/springframework/aop/scope/ScopedProxyBeanRegistrationAotProcessor.java

@@ -163,8 +163,8 @@ class ScopedProxyBeanRegistrationAotProcessor implements BeanRegistrationAotProc
 						method.addStatement("return ($T) factory.getObject()",
 								beanClass);
 					});
-			return CodeBlock.of("$T.of($T::$L)", InstanceSupplier.class,
-					beanRegistrationCode.getClassName(), generatedMethod.getName());
+			return CodeBlock.of("$T.of($L)", InstanceSupplier.class,
+					generatedMethod.toMethodReference().toCodeBlock());
 		}
 
 	}