In Javascript, `typeof x !== undefined ? t : f` should act like a declaration of `x` in the true branch

Search Terms:
existence of define typeof undefined

Code

// @noEmit: true
// @allowJs: true
// @checkJs: true
// @strict: true
// @Filename: a.js
if (typeof define !== 'undefined' && define.amd) {
    define([], function() {
    })
}
// also, nested
exports.storage = 'undefined' != typeof chrome &&
    'undefined' != typeof chrome.storage ?
    chrome.storage.local :
    undefined;

Expected behavior:
The check type define !== undefined should cause the true branch of the conditional to act as if define were declared.

Actual behavior:
Cannot find name 'define'.

Start with the a.js reproduction and its @allowJs, @checkJs, and @strict settings, then run the TypeScript checker against the two typeof patterns. Trace how the checker handles the conditional branches and unresolved names. Done means both examples type-check without a Cannot find name error while preserving the existing behavior for nested checks.