[@babel/traverse]: Allowed node aliases as keys in visitors.

[cameron-martin]

This is made possible by babel/babel#9110.

When the next version after v7.2.2 is released, the package.json can be updated and the build will no longer fail.

Please fill in this template.

• Use a meaningful title for the pull request. Include the name of the package modified.
• Test the change in your own code. (Compile and run.)
• Add or edit tests to reflect the change. (Run with npm test.)
• Follow the advice from the readme.
• Avoid common mistakes.
• Run npm run lint package-name (or tsc if no tslint.json is present).

Select one of these and delete the others:

If changing an existing definition:

• Provide a URL to documentation or source code which provides context for the suggested changes: https://github.com/jamiebuilds/babel-handbook/blob/master/translations/en/plugin-handbook.md#toc-visitors
• Increase the version number in the header if appropriate.
• If you are making substantial changes, consider adding a tslint.json containing { "extends": "dtslint/dt.json" }.

[typescript-bot]

@cameron-martin Thank you for submitting this PR!

🔔 @yortus @marvinhagemeister @rpetrich @mgroenhoff - please review this PR in the next few days. Be sure to explicitly select Approve or Request Changes in the GitHub UI so I know what's going on.

If no reviewer appears after a week, a DefinitelyTyped maintainer will review the PR instead.

[typescript-bot]

@cameron-martin The Travis CI build failed! Please review the logs for more information.

Once you've pushed the fixes, the build will automatically re-run. Thanks!

[typescript-bot]

@cameron-martin I haven't seen anything from you in a while and this PR currently has problems that prevent it from being merged. The PR will be closed tomorrow if there aren't new commits to fix the issues.

[cameron-martin]

A new version of @babel/types wasn't released when new versions of other packages are released. I've filed this as a bug. babel/babel#9239

[typescript-bot]

@cameron-martin To keep things tidy, we have to close PRs that aren't mergeable but don't have activity from their author. No worries, though - please open a new PR if you'd like to continue with this change. Thank you!

[cameron-martin]

Reopened as #32395