Support extension modules built in-place

[brettcannon]

Microsoft/vscode-python#2466

If you do python3 setup.py build_ext --inplace for e.g. _hellomodule.c on maOS you end up with a _hello.cpython-37m-darwin.so file in the same directory as setup.py. The language server is not picking the module up for analysis even though it can be imported thanks to being in the current working directory.

[MikhailArkhipov]

This is b/c we do not watch the workspace paths. If we did't we'd be reloading modules on each file save including temp backups VS Code creates. The solution needs mechanism on what to watch and what to ignore in order to determine what changed in the importable set.

[MikhailArkhipov]

#1076

[shelper]

any update? the completion support for such module works in native python shell. why it has problem with the language server?

[brettcannon]

@shelper there's no update and development of MPLS has mostly moved over to Pylance at this point.

[chopin1998]

similar problem. a C module (*.so lib file) can dynamic detected by ipython, but vscode cannot