Crash for completion at beginning of JSX closing tag when intrinsic not defined

[DanielRosenwasser]

Don't use a react.d.ts of any sort.

var x = <div></

Request completion at the end

Expected: No tears, only dreams.
Actual: Tears

Description:

getCompletionsAtPosition('C:\Users\drosen\AppData\Local\Temp\~vs88A1.tsx', 15)

StackTrace:

TypeError: Unable to get property 'flags' of undefined or null reference
   at buildSymbolDisplay (:15602:17)
   at symbolToString (:15483:13)
   at getDeclaredName (:42053:9)
   at getCompletionEntryDisplayNameForSymbol (:46776:13)
   at createCompletionEntry (:47587:17)
   at getCompletionEntriesFromSymbols (:47611:25)
   at getCompletionsAtPosition (:47545:17)
   at Anonymous function (:52055:17)
   at simpleForwardCall (:51773:9)
   at forwardJSONCall (:51789:13)
   at forwardJSONCall (:51835:13)
   at getCompletionsAtPosition (:52054:13)

[DanielRosenwasser]

Actually, you can even request completion and crash with JSX defined

namespace JSX {
    interface IntrinsicElements {
        prop: any
    }
}

var x =
    <prop>

    </prop/**/>

[yuit]

For the first example, the problem is that type-checker can't find the type in the of the modulereact as such module will not existed when users don't include react.d.ts. I discussed with @RyanCavanaugh a bit and it may be a good idea to just return the opening tag name.

[yuit]

the second example crash because prop is not visible outside of the namespace. It should be

namespace JSX {
    export interface IntrinsicElements {
        prop: any
    }
}

var x =
    <prop>

    </prop/**/>

Though in general, we should handle more graceful when we can't find tag element