basename: true and unixify: true breaks .not()

[rogierschouten]

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Please describe the minimum necessary steps to reproduce this issue:

$ node
> let mm = require("micromatch")
undefined
> mm.not(["C:\\bla\\bar.xml"], ["*.xml"], {basename: true, unixify: true})
[ 'C:\\bla\\bar.xml' ]
> mm.not(["C:\\bla\\bar.xml"], ["*.xml"], {basename: true, unixify: false})
[]
> mm.not(["C:\\bla\\bar.xml"], ["**/*.xml"], {basename: false, unixify: true})
[ 'C:\\bla\\bar.xml' ]
> mm.not(["C:\\bla\\bar.xml"], ["**/*.xml"], {basename: false, unixify: false})
[]
>

…

What is happening (but shouldn't):

Specifying basename: true and unixify: true on Windows breaks the .not() function (inverts its logic)

…

What should be happening instead?

Specifying basename: true and unixify: true on Windows does not break the .not() function (inverts its logic)

…

[doowb]

I have a fix for this (tested on mac and windows). I'll submit a PR in a bit.