Fast path for Array#pop(1)

[ggrossetie]

Command

$ bundle exec rake bench:ips FILE=benchmark-ips/bm_array_pop_1.rb

Before (Node 14)

=== Files: benchmark-ips/bm_array_pop_1.rb
bundle exec opal --dynamic-require ignore --missing-require ignore -ropal/platform -gbenchmark-ips -rbenchmark/ips -A benchmark-ips/bm_array_pop_1.rb
Warming up --------------------------------------
              pop(1)    33.930k i/100ms
Calculating -------------------------------------
              pop(1)    552.367k (± 2.9%) i/s -      2.782M in   5.041536s

After (Node 14)

=== Files: benchmark-ips/bm_array_pop_1.rb
bundle exec opal --dynamic-require ignore --missing-require ignore -ropal/platform -gbenchmark-ips -rbenchmark/ips -A benchmark-ips/bm_array_pop_1.rb
Warming up --------------------------------------
              pop(1)    41.379k i/100ms
Calculating -------------------------------------
              pop(1)    803.658k (± 4.9%) i/s -      4.014M in   5.007475s

Summary

With this change, the code is now ~1.4x times faster.

[ggrossetie]

Thanks 👍