remove hack to handle VS2015-Express

[refack]

Summary of changes

Remove a 10 year old hack needed to acomodated VS2015 Express that was introduced in bafe9fb

Pull Request Checklist

• Changes have tests
• News fragment added in newsfragments/.
  (See documentation for details)

[refack]

I wanted to gauge the mood WRT this change, so I posted this as a draft.
For me the current logic fails since I trimmed my build toolset and removed the x86 and arm* hosts since my machine is x64.
If there are no objection on principal, I'll try to come up with a test.

[abravalheri]

Hi @refack , please note that any changes in the _distutils folder should be directed to the pypa/distutils repository.

I would also recommend adding some text with the motivation behind the change (e.g. what does it improve? What does it make possible?...) and some assessment regarding the likelihood there is people out there relying on the old implementation and if it would break their setups.

[refack]

@abravalheri thank you. Noted.