Add a cache to `BridgeMethodResolver` to help with repeated calls to
resolve the same methods. Since bridge method resolution can be somewhat
expensive (especially when resolving generics), and the number of bridge
methods is quite small, a cache generally helps.
This commit also simplifies the code a little by calling `doWithMethods`
directly rather than relying on `ReflectionUtils.getAllDeclaredMethods`
to do so. The methods list is now always created, but we save the list
creation that `getAllDeclaredMethods` used to do.
Closes gh-22579
db8eaec131