[windows] Use quotes to allow spaces in path

[tusharpm]

The following changes are proposed:

• Quotes around vswhere_exe path.

The purpose of this change

For the case where vswhere_exe path has a whitespace character.

Other Notes/Information

On Windows, my username has a whitespace ("Tushar Maheshwari" in my case).
VS Code stores the installed extensions, and their resources in the home directory, which has the username in the path.
The extension uses vswhere without quotes, which fails with:

'C:\Users\Tushar' is not recognized as an internal or external command, operable program or batch file.

Tried locally with the changes, the extension succeeds in executing vswhere and continues execution.

[no-realm]

Is shell mode necessary here?

[tusharpm]

I tried without setting it. It reported something like:

'\"C:\Users\Tushar Maheshwari\[...]\vswhere.exe\"' is not recognized as an internal or external command, operable program or batch file.

It escaped the quotes because of the missing windowsVerbatimArguments (default: false).
The existing proc.execute does not pass that option to child_process.spawn, like it does shell.
According to the documentation, the former "is set to true automatically when shell is specified."

Therefore, although the shell mode might not exactly be necessary, it helps in the fix here.
The alternative is to modify proc.ts:execute to pass windowVerbatimArguments also.
Thoughts?

[vector-of-bool]

Sorry for the slow response. Does setting windowsVerbatimArguments work? I'm disinclined to ever use shell, but we'll have to if nothing else works.

I'm hoping to push 0.11.1 today and want to get this in the release.

[tusharpm]

I attempted this in 7374792.
I got:

$ npm run compile
src/proc.ts(109,5): error TS2322: Type '{ env: EnvironmentVariables; shell: boolean; windowsVerbatimArguments: boolean; }' is not assignable to type 'SpawnOptions'.
  Object literal may only specify known properties, and 'windowsVerbatimArguments' does not exist in type 'SpawnOptions'.

I checked @type/node v8.0.30 index.d.ts (automatically installed by npm install), SpawnOptions doesn't declare windowVerbatimArguments as a member.

However, the generated out/src/proc.js resembles the expected output.
Should I pull that commit to this branch?

[vector-of-bool]

Nah, just use shell. The NodeJS version shipping with VSCode is a little outdated so the docs might not match what's available in the VSCode version. Tell me when you're ready to merge.

[tusharpm]

Oh, I tested that change in a different branch. This one should be alright to merge if shell is acceptable.

[vector-of-bool]

@Randshot could you follow up on your review? I can override and do the merge without your review, but I'd rather not.