[Backport Request] Fix ReactCommon Break for Windows

[chiaramooney]

Summary

Changes to MapBuffer code in aaff15c...d287598 broke build for Windows. Errors included incompatible type conversions, the use of __attribute__(__packed__) which is only supported by GCC and Clang, and the usage of designated initializers which are only supported on C++20.

Changes here restore build on Windows.

Original PR: #33047

Changelog

[General] [Fixed] - Fix build break on Windows with ReactCommon

Test Plan

React Native project built on Windows and passes react-native-windows repository pipeline. These edits are currently merged into the main branch of react-native-windows.

[pull-bot]

	Fails
🚫	node` failed.

Log

Error:  RequestError [HttpError]: Must have admin rights to Repository.
    at /root/react-native/bots/node_modules/@octokit/request/dist-node/index.js:86:21
    at processTicksAndRejections (internal/process/task_queues.js:95:5) {
  status: 403,
  response: {
    url: 'https://api.github.com/repos/facebook/react-native/issues/33086/labels',
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    headers: {
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      connection: 'close',
      'content-encoding': 'gzip',
      'content-security-policy': "default-src 'none'",
      'content-type': 'application/json; charset=utf-8',
      date: 'Thu, 10 Feb 2022 22:51:22 GMT',
      'referrer-policy': 'origin-when-cross-origin, strict-origin-when-cross-origin',
      server: 'GitHub.com',
      'strict-transport-security': 'max-age=31536000; includeSubdomains; preload',
      'transfer-encoding': 'chunked',
      vary: 'Accept-Encoding, Accept, X-Requested-With',
      'x-accepted-oauth-scopes': '',
      'x-content-type-options': 'nosniff',
      'x-frame-options': 'deny',
      'x-github-media-type': 'github.v3; format=json',
      'x-github-request-id': '9466:93BD:102CBB3:254C192:620596EA',
      'x-oauth-scopes': 'public_repo',
      'x-ratelimit-limit': '5000',
      'x-ratelimit-remaining': '4992',
      'x-ratelimit-reset': '1644537081',
      'x-ratelimit-resource': 'core',
      'x-ratelimit-used': '8',
      'x-xss-protection': '0'
    },
    data: {
      message: 'Must have admin rights to Repository.',
      documentation_url: 'https://docs.github.com/rest/reference/issues#add-labels-to-an-issue'
    }
  },
  request: {
    method: 'POST',
    url: 'https://api.github.com/repos/facebook/react-native/issues/33086/labels',
    headers: {
      accept: 'application/vnd.github.v3+json',
      'user-agent': 'octokit.js/16.43.2 Node.js/14.18.1 (Linux 5.11; x64)',
      authorization: 'token [REDACTED]',
      'content-type': 'application/json; charset=utf-8'
    },
    body: '{"labels":["Pick Request"]}',
    request: { hook: [Function: bound bound register] }
  }
}
danger-results://tmp/danger-results.json

Generated by 🚫 dangerJS against 78452b5

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
ios	-	universal	n/a	--

Base commit: 9bc6c0f
Branch: main

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
android	hermes	arm64-v8a	8,125,225	-62,802
android	hermes	armeabi-v7a	7,726,129	-62,329
android	hermes	x86	8,495,399	-62,712
android	hermes	x86_64	8,447,534	-62,973
android	jsc	arm64-v8a	9,790,660	-66,418
android	jsc	armeabi-v7a	8,776,400	-66,002
android	jsc	x86	9,757,431	-66,343
android	jsc	x86_64	10,353,597	-66,642

Base commit: 9bc6c0f
Branch: main

[lunaleaps]

Interesting, looks like the DangerJS bot needs to be using an account that has write permissions to add the label (unrelated to this PR -- sorry most folks haven't been creating pick request PRs so we're still fixing up the process -- so thank you for doing so!)

K going to land this (heads up @ShikaSD)

[ShikaSD]

Thanks, @lunaleaps, I was planning to pick this manually for the next rc anyways ;)