Before this change AbstractHandlerMethodMapping used a map from Method
to CorsConfiguration. That works for regular @RequestMapping methods.
However frameworks like Spring Boot and Spring Integration may
programmatically register the same Method under multiple mappings,
i.e. adapter/gateway type classes.
This change ensures that CorsConfiguraiton is indexed by HandlerMethod
so that we can store CorsConfiguration for different handler instances
even when the method is the same.
In order for to make this work, HandlerMethod now provides an
additional field called resolvedFromHandlerMethod that returns the
original HandlerMethod (with the String bean name). This makes it
possible to perform reliable lookups.
Issue: SPR-11541
8853107f76