with thunk state being shareable we no longer need to worry about value
uniqueness, only about value lifetime. this means we can liberally drop
indirections and allocations, passing references instead of pointers or
using stack memory instead of gc-managed memory for some intermediates.
Change-Id: I2d48a6fd57a376d544bd9bd2d05e5420611986d1
eldritch horrors
db35aa753b