Merge branch 'master' into inlinec

Merge branch 'master' into inlinec

* master:
  struct-arrays and struct-vectors: fix unit tests
  oops
  byte-length for struct-vectors
  fix struct-vectors
  sequences: fix replicate example
  byte-length method for struct-arrays
  growable vocabulary: make 'contract' generic so that only real vectors clear popped elements; add resize method for struct-arrays, add new struct-vectors vocabulary
  Add vectors.functor for generating vector types from arrays; re-implement bit-vectors and specialized-vectors using this. Add DEFERS directive to functors
  compiler.cfg.linear-scan: debugging spilling, add more assertions
  threads: better error messages
  benchmark.hashtables: throw something together
  Remove A+s shortcut for saving image in UI
  compiler.cfg.linear-scan: code cleanup
  compiler.cfg.linear-scan: Re-implement spilling, add some additional runtime assertions, simplify assignment pass since it doesn't have to track spill slots anymore; just assume a live value that's not in active or inactive is spilled