Stop exposing some internals on FB build

[gaearon]

These are no longer used. Test plan: tbgs.

[sizebot]

No significant bundle size changes to report.

Size changes (stable)

Generated by 🚫 dangerJS against e0f4c50

[sizebot]

Details of bundled changes.

Comparing: 517de74...e0f4c50

react-dom

File	Filesize Diff	Gzip Diff	Prev Size	Current Size	Prev Gzip	Current Gzip	ENV
react-dom-unstable-fizz.browser.production.min.js	0.0%	-0.3%	1.21 KB	1.21 KB	711 B	709 B	UMD_PROD
react-dom-test-utils.production.min.js	0.0%	-0.0%	11.21 KB	11.21 KB	4.17 KB	4.17 KB	UMD_PROD
react-dom-test-utils.development.js	0.0%	-0.0%	53.66 KB	53.66 KB	15.27 KB	15.27 KB	NODE_DEV
react-dom-test-utils.production.min.js	0.0%	-0.0%	10.99 KB	10.99 KB	4.1 KB	4.1 KB	NODE_PROD
react-dom-unstable-native-dependencies.development.js	0.0%	-0.0%	60.93 KB	60.93 KB	16.08 KB	16.08 KB	UMD_DEV
react-dom-unstable-fizz.node.production.min.js	0.0%	-0.1%	1.21 KB	1.21 KB	698 B	697 B	NODE_PROD
ReactDOM-dev.js	-0.0%	+0.1%	986.73 KB	986.59 KB	218.2 KB	218.32 KB	FB_WWW_DEV
react-dom-unstable-fizz.browser.production.min.js	0.0%	-0.2%	1.05 KB	1.05 KB	642 B	641 B	NODE_PROD
ReactDOM-prod.js	-0.1%	-0.0%	393.59 KB	393.39 KB	71.93 KB	71.92 KB	FB_WWW_PROD
ReactDOM-profiling.js	-0.0%	-0.0%	404.84 KB	404.64 KB	74.09 KB	74.08 KB	FB_WWW_PROFILING
react-dom-testing.profiling.min.js	0.0%	-0.0%	121.12 KB	121.12 KB	39.04 KB	39.04 KB	UMD_PROFILING
react-dom-testing.development.js	0.0%	0.0%	956.65 KB	956.65 KB	214.4 KB	214.4 KB	NODE_DEV
ReactDOMTesting-dev.js	0.0%	0.0%	985.25 KB	985.25 KB	217.47 KB	217.47 KB	FB_WWW_DEV

ReactDOM: size: 0.0%, gzip: -0.3%

Size changes (experimental)

Generated by 🚫 dangerJS against e0f4c50

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Sandbox	Source
pensive-waterfall-b66i4	Configuration