Rewrite reconcileChildrenArray and reconcileChildrenIterator

[ghost]

For mount, create and exit.
Based on the newChild traversal, no matching old node is added to the Map.

[sizebot]

Comparing: 35f7441...27cb834

Critical size changes

Includes critical production bundles, as well as any change greater than 2%:

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
oss-stable/react-dom/cjs/react-dom.production.min.js	=	122.34 kB	122.34 kB	=	39.42 kB	39.42 kB
oss-experimental/react-dom/cjs/react-dom.production.min.js	=	128.91 kB	128.91 kB	=	41.47 kB	41.47 kB
facebook-www/ReactDOM-prod.classic.js	=	405.61 kB	405.61 kB	=	75.10 kB	75.10 kB
facebook-www/ReactDOM-prod.modern.js	=	393.95 kB	393.95 kB	=	73.28 kB	73.28 kB
facebook-www/ReactDOMForked-prod.classic.js	=	405.62 kB	403.50 kB	=	75.10 kB	74.76 kB

Significant size changes

Includes any change greater than 0.2%:

Expand to show

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
facebook-www/ReactDOMForked-profiling.classic.js	=	424.50 kB	422.40 kB	=	78.39 kB	78.06 kB
facebook-www/ReactDOMForked-profiling.modern.js	=	412.80 kB	410.70 kB	=	76.54 kB	76.20 kB
facebook-www/ReactDOMForked-prod.classic.js	=	405.62 kB	403.50 kB	=	75.10 kB	74.76 kB
facebook-www/ReactDOMForked-prod.modern.js	=	393.96 kB	391.85 kB	=	73.27 kB	72.93 kB
facebook-www/ReactDOMForked-dev.classic.js	=	1,049.40 kB	1,042.11 kB	=	232.15 kB	230.77 kB
facebook-www/ReactDOMForked-dev.modern.js	=	1,023.20 kB	1,015.91 kB	=	227.02 kB	225.64 kB

Generated by 🚫 dangerJS against 27cb834