Fixes crash on chained property access on require

[sandersn]

From the user tests:

const x = require('y').z.ka

would cause the crash because I forgot to call
getLeftMmostPropertyAccessExpression in one place.

Note that we still get the import wrong, it just stops the crash.

[DanielRosenwasser]

What was the original stack trace? Does this fix any of the issues found by the fuzzer?

[sandersn]

TypeError: Cannot read property '0' of undefined
    at getTargetOfImportEqualsDeclaration (/home/nathansa/ts/built/local/tsc.js:44281:65)
    at getTargetOfAliasDeclaration (/home/nathansa/ts/built/local/tsc.js:44633:28)
    at resolveAlias (/home/nathansa/ts/built/local/tsc.js:44681:30)
    at getSymbol (/home/nathansa/ts/built/local/tsc.js:43338:38)
    at resolveNameHelper (/home/nathansa/ts/built/local/tsc.js:43611:34)
    at resolveName (/home/nathansa/ts/built/local/tsc.js:43595:20)
    at getResolvedSymbol (/home/nathansa/ts/built/local/tsc.js:60627:21)
    at checkIdentifier (/home/nathansa/ts/built/local/tsc.js:62498:26)
    at checkExpressionWorker (/home/nathansa/ts/built/local/tsc.js:69870:28)
    at checkExpression (/home/nathansa/ts/built/local/tsc.js:69820:38)

Where are the issues found by the fuzzer?