Use AS::N build_handle API in Rails::Rack::Logger
Use AS::N build_handle API in Rails::Rack::Logger

Rails::Rack::Logger is one of the few (the only?) places where we aren't
able to use the preferred AS::N.instrument API with a block. This is
because we want to finish the event when the Rack body is closed, rather
than when the status and headers are first returned.

This switches to using the low-level `build_handle` API, which allows
safe interleaving of events and doesn't make use of thread or fiber
locals.

georgeclaghorn/rails,MSP-Greg/rails,yahonda/rails,BlakeWilliams/rails,Erol/rails,rails/rails,georgeclaghorn/rails,yahonda/rails,esparta/rails,kmcphillips/rails,rails/rails,yawboakye/rails,rails/rails,Erol/rails,kmcphillips/rails,esparta/rails,Erol/rails,rails/rails,esparta/rails,yahonda/rails,kmcphillips/rails,yawboakye/rails,BlakeWilliams/rails,BlakeWilliams/rails,georgeclaghorn/rails,Erol/rails,yahonda/rails,MSP-Greg/rails,georgeclaghorn/rails,MSP-Greg/rails,yawboakye/rails,kmcphillips/rails,MSP-Greg/rails,esparta/rails,BlakeWilliams/rails,yawboakye/rails