No completions for sys.exc_info with latest typeshed

[huguesv]

With the bundled typeshed on Python 3, you get completions/info tips on these variables:

import sys
e1, e2, e3 = sys.exc_info()

But if you clone latest typeshed and make vscode use that (I overwrote the languageSever.x.y.z/Typeshed folder) then you no longer get completions/info tips.

microsoft/PTVS#4877

[jakebailey]

I'm willing to bet it's because of this: python/typeshed@25ac4d6

exc_info()'s return value was changed from a plain tuple into _OptExcInfo, which is:

_OptExcInfo = Tuple[Optional[Type[BaseException]], Optional[BaseException], Optional[TracebackType]]

Whether or not it's due to the Optional or due to the fact that it changed from an inline type to one that's assigned, I don't know offhand.

[jakebailey]

This was almost fixed as of #546 (e1 and e2 have types), but TracebackType doesn't seem to get resolved even though it's been imported in the stub.

[jakebailey]

Looked at this more closely; sys.pyi imports types (which would be types.pyi) and types.pyi imports sys (to do those simple if statements).

[jakebailey]

This looks to be fixed, though the tooltips could use some work.