path.evaluate wrongly retruns with confidence for "block-scoped" var's

[mjesun]

Bug Report

Current Behavior
path.evaluate is broken for var scopes.

Input Code
http://astexplorer.net/#/gist/583ea7d0c0501af69a1b224526f7f864

Expected behavior/code
Cannot return with confidence that doesExist is true.

Babel Configuration (.babelrc, package.json, cli command)
N/A

Environment
N/A

[babel-bot]

Hey @mjesun! We really appreciate you taking the time to report an issue. The collaborators
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so it's possible this won't be addressed swiftly.

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[mjesun]

And, like #8017, this also affects the minifier.