Git integration and built-in terminal do not "understand" from which root the current file is open

[dr-nafanya]

• VSCode Version: 1.15 - Insiders
• OS Version: macOS Sierra 10.12.5

Steps to Reproduce:

1. Create a multi-root workspace, where every root is separate repository, for example roots A, B and C.
2. Try opening file from root A and then from B and then from C.

The following issues are observed:

1. The VS Code Git integration does not "understand" from which root/repository the file is open and hence cannot highlight the changes in file opened from roots B and C.
2. The built-in terminal also does not "understand" from which root the current file is open, and no matter from which root the file is open, will still be opening the root A directory.

Reproduces without extensions: Yes

[joaomoreno]

Duplicate of #31325