from typing import Callable doesnt trigger correct IntelliSense

[hanpari]

Issue Type: Bug

After
from typing import C..

VS Code cannot offer Callable and others (see ipython picture import bellow).

The same behaviour I checked on Python 3.7 and 3.6, on windows Python and Linux Python virtualized under Windows.
I confirmed the same issue on a different Window machine as well.

I checked Python source code whether Callable is listed in __all__ and everything seems fine.

Extension version: 2019.9.34911
VS Code version: Code 1.38.1 (b37e54c98e1a74ba89e03073e5a3761284e3ffb0, 2019-09-11T13:35:15.005Z)
OS version: Windows_NT x64 10.0.17763

System Info

Item	Value
CPUs	Intel(R) Pentium(R) CPU 2020M @ 2.40GHz (2 x 2395)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: disabled_off native_gpu_memory_buffers: disabled_software oop_rasterization: disabled_off protected_video_decode: enabled rasterization: enabled skia_deferred_display_list: disabled_off skia_renderer: disabled_off surface_synchronization: enabled_on video_decode: unavailable_off viz_display_compositor: disabled_off webgl: enabled webgl2: enabled
Load (avg)	undefined
Memory (System)	7.88GB (1.25GB free)
Process Argv	.
Screen Reader	no
VM	0%

Import works fine

IPython works as expected

[jakebailey]

This is #535. We implement the typing module in the LS directly (as it is a part of our type system), and some members have not yet been implemented.