Facebook: merge react index.classic.fb and index.modern.fb

[kassens]

Facebook: merge react index.classic.fb and index.modern.fb

These export the same.

NOTE: The 2 builds are still different based on flags and other forked files.

[react-sizebot]

Comparing: 6946ebe...b88769d

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.js	=	6.66 kB	6.66 kB	+0.05%	1.82 kB	1.82 kB
oss-stable/react-dom/cjs/react-dom-client.production.js	=	494.06 kB	494.06 kB	=	88.21 kB	88.22 kB
oss-experimental/react-dom/cjs/react-dom.production.js	=	6.67 kB	6.67 kB	+0.05%	1.83 kB	1.83 kB
oss-experimental/react-dom/cjs/react-dom-client.production.js	=	498.86 kB	498.86 kB	=	88.93 kB	88.93 kB
facebook-www/ReactDOM-prod.classic.js	=	591.22 kB	591.22 kB	=	103.96 kB	103.96 kB
facebook-www/ReactDOM-prod.modern.js	=	567.44 kB	567.44 kB	=	100.36 kB	100.36 kB
test_utils/ReactAllWarnings.js	Deleted	64.26 kB	0.00 kB	Deleted	16.02 kB	0.00 kB

Significant size changes

Includes any change greater than 0.2%:

Expand to show

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
test_utils/ReactAllWarnings.js	Deleted	64.26 kB	0.00 kB	Deleted	16.02 kB	0.00 kB

Generated by 🚫 dangerJS against b88769d