Fix "illegal hardware instruction" in ch6-particles on MacOS#106

ckoopmann wants to merge 2 commits intorust-in-action:1st-editionrust-in-action/code:1st-editionfrom

ckoopmann:ch6-particles-fix-illegal-hardware-instruction-panic-on-macosckoopmann/code:ch6-particles-fix-illegal-hardware-instruction-panic-on-macosCopy head branch name to clipboard