bpfilter

Currently, matcher codegen is hardcoded in a flavor-agnostic switch. With this refactor, each flavor controls its own matcher codegen through a callback, allowing a new flavor to intercept matchers and generate context-appropriate bytecode. The callback generalizes the ad-hoc and callbacks. Instead of having dedicated callbacks for each flavor-sensitive value, every flavor controls its full matcher codegen through a single dispatch point. Packet-based flavors delegate most matchers to a shared function (the extracted switch), overriding only the matchers that need flavor-specific context access. Here is an overview of the architectural changes: Current Architecture bf\_flavor\_ops (7 callbacks): Problem: There is no simple mechanism for a flavor to provide alternative bytecode for the same matcher type. The only two flavor-aware matchers ( and ) use ad-hoc callbacks rather than a general dispatch mechanism. New Architecture (After) bf\_flavor\_ops (6 callbacks):** Notes: Commit a65aca1 adds a missing load instruction that is moved as part of this PR. While this enables flavor-specific matching in a more intuitive way, an even better approach would be a callback-centric approach that let's flavors define their own table of callbacks per matcher. The plan is to add this eventually.