Setup Wave 2 of Feature Flags for React Native

[yungsters]

Summary

Sets up dynamic feature flags for disableStringRefs, enableFastJSX, and enableRefAsProp in React Native (at Meta).

How did you test this change?

$ yarn test
$ yarn flow fabric

[react-sizebot]

Comparing: 46abd7b...997a160

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	=	1.82 kB	1.82 kB
oss-stable/react-dom/cjs/react-dom-client.production.js	=	492.61 kB	492.61 kB	=	87.88 kB	87.88 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	88.92 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
facebook-react-native/react/cjs/JSXRuntime-prod.js	+40.58%	2.98 kB	4.19 kB	+18.53%	1.27 kB	1.50 kB
facebook-react-native/react/cjs/JSXRuntime-profiling.js	+40.58%	2.98 kB	4.19 kB	+18.53%	1.27 kB	1.50 kB
facebook-react-native/react/cjs/React-prod.js	+9.22%	21.25 kB	23.20 kB	+6.42%	5.61 kB	5.97 kB
facebook-react-native/react/cjs/React-profiling.js	+9.03%	21.68 kB	23.64 kB	+6.33%	5.69 kB	6.05 kB
facebook-react-native/react/cjs/JSXDEVRuntime-dev.js	+8.96%	47.31 kB	51.55 kB	+7.70%	13.64 kB	14.69 kB
facebook-react-native/react/cjs/JSXRuntime-dev.js	+8.73%	48.54 kB	52.78 kB	+7.45%	14.01 kB	15.05 kB
facebook-react-native/react/cjs/React-dev.js	+4.35%	109.92 kB	114.70 kB	+3.77%	28.93 kB	30.02 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
facebook-react-native/react/cjs/JSXRuntime-prod.js	+40.58%	2.98 kB	4.19 kB	+18.53%	1.27 kB	1.50 kB
facebook-react-native/react/cjs/JSXRuntime-profiling.js	+40.58%	2.98 kB	4.19 kB	+18.53%	1.27 kB	1.50 kB
facebook-react-native/react/cjs/React-prod.js	+9.22%	21.25 kB	23.20 kB	+6.42%	5.61 kB	5.97 kB
facebook-react-native/react/cjs/React-profiling.js	+9.03%	21.68 kB	23.64 kB	+6.33%	5.69 kB	6.05 kB
facebook-react-native/react/cjs/JSXDEVRuntime-dev.js	+8.96%	47.31 kB	51.55 kB	+7.70%	13.64 kB	14.69 kB
facebook-react-native/react/cjs/JSXRuntime-dev.js	+8.73%	48.54 kB	52.78 kB	+7.45%	14.01 kB	15.05 kB
facebook-react-native/react/cjs/React-dev.js	+4.35%	109.92 kB	114.70 kB	+3.77%	28.93 kB	30.02 kB
react-native/implementations/ReactFabric-prod.fb.js	+0.36%	364.86 kB	366.17 kB	+0.59%	63.75 kB	64.13 kB
react-native/implementations/ReactNativeRenderer-prod.fb.js	+0.35%	372.20 kB	373.51 kB	+0.56%	65.06 kB	65.42 kB
react-native/implementations/ReactFabric-profiling.fb.js	+0.33%	392.16 kB	393.46 kB	+0.55%	67.98 kB	68.35 kB
react-native/implementations/ReactNativeRenderer-profiling.fb.js	+0.33%	399.44 kB	400.74 kB	+0.54%	69.35 kB	69.73 kB
test_utils/ReactAllWarnings.js	Deleted	64.26 kB	0.00 kB	Deleted	16.02 kB	0.00 kB

Generated by 🚫 dangerJS against 997a160