improve cost of instrumentation by up to 15x in chrome
improve cost of instrumentation by up to 15x in chrome

Note: This is only enabled if someone engages the inspector, or manually enables instrumentation.
Rich-Harris/rsvp.js,tildeio/rsvp.js,imshibaji/rsvp.js,imshibaji/rsvp.js,alpapad/rsvp.js,Rich-Harris/rsvp.js,waraujodesign/rsvp,twokul/rsvp.js,twokul/rsvp.js,tildeio/rsvp.js,alpapad/rsvp.js,waraujodesign/rsvp,seanpdoyle/rsvp.js,MSch/rsvp.js,seanpdoyle/rsvp.js,MSch/rsvp.js