Reorg + Spiral Explorer + Perf#1

Open

jacobrosenthal wants to merge 14 commits intoagajews:masterfrom

jacobrosenthal:spiral

Commits on Sep 25, 2020

Commits on Sep 27, 2020

use compiler controlled overflow assert on debug only
jacobrosenthal
committed
add bench for upstream algo, and upstream algo using my allocation and debug changes
jacobrosenthal
committed