verify-windows.ps1 script doesn't search for prerelease VisualStudio installs

[stevekiene]

$vsWhereOutput = (& $vswhere -format xml)

Might want to consider having the -prerelease flag to add searches for non-release versions of VS. Otherwise the script fails when a user only has prerelease versions installed.

[schultetwin1]

Ah, good call. I'll add that

[schultetwin1]

Whoops, referenced wrong PR.

[schultetwin1]

@stevekiene this should now be fixed. We are also now validating builds under VS2019 so building using VS2019 should be build break free. We are also unit testing the bits from VS2019 but not testing them against actual hardware, so you have a slight chance of running into an issue there.