2x regression in split() performance

using BenchmarkTools
@btime split("str,str,str,str,str,str,str", ",")

In v0.6:

 286.683 ns (10 allocations: 432 bytes)

In v0.7:

  567.859 ns (16 allocations: 624 bytes)

[ViralBShah]

I get 650ns on 0.7-master and 426ns on 0.6.2.

[KristofferC]

These are almost the same now (270 ns vs 300 ns). Think this can be closed.