Errant `case` causes crash in `switch`/`case` snippet completions

[DanielRosenwasser]

switch (Math.random() ? 123 : 456) {
     case "oops!":
     case$
}

Ensure you have snippet completions enabled and request completions at $.

Request completion entry details for the snippet completion case 123...

TypeError: Cannot destructure property 'entry' of 'getExhaustiveCaseSnippets(...)' as it is undefined.
    at Object.getCompletionEntryDetails (.../node_modules/typescript/lib/tsserver.js:158306:15)
    at Object.getCompletionEntryDetails2 [as getCompletionEntryDetails] (.../node_modules/typescript/lib/tsserver.js:144582:35)
    at .../node_modules/typescript/lib/tsserver.js:184151:43
    at mapDefined (.../node_modules/typescript/lib/tsserver.js:2668:22)
    at IpcIOSession.getCompletionEntryDetails (.../node_modules/typescript/lib/tsserver.js:184149:20)
    at completionEntryDetails (.../node_modules/typescript/lib/tsserver.js:182478:43)
    at .../node_modules/typescript/lib/tsserver.js:184857:69
    at IpcIOSession.executeWithRequestId (.../node_modules/typescript/lib/tsserver.js:184849:14)
    at IpcIOSession.executeCommand (.../node_modules/typescript/lib/tsserver.js:184857:29)
    at IpcIOSession.onMessage (.../node_modules/typescript/lib/tsserver.js:184899:51)
    at process.<anonymous> (.../node_modules/typescript/lib/tsserver.js:186480:14)