Add support for Windows ARM64 - #90

Let me know when you are happy and I'll merge this and tag a release, easiest way to have AppVeyor generate a build, see what happens.

Let me know when you are happy and I'll merge this and tag a release, easiest way to have AppVeyor generate a build, see what happens.

👍
I think the change is good to go. If Appveyor build fails e.g. due to missing ARM64 build tools, we can probably comment-out the two added Msvs calls using arm64 for now.

Thank you!

Build is queued

https://ci.appveyor.com/project/cefsharp/cef-binary-5r1rw/builds/37278296

The build failed when trying to build for x86 with v140 toolchain (but the arm64 build with v141 toolchain apparently succeeded):

C:\projects\cef-binary-5r1rw>"C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\Tools\..\..\vc\vcvarsall.bat" x86   && set  1>"C:\Users\appveyor\AppData\Local\Temp\1\tmp33BB.tmp" 
Caught an exception: The input line is too long.
	Exception Type: System.Management.Automation.RemoteException
	Stack Trace: at Invoke-BatchFile, C:\projects\cef-binary-5r1rw\build.ps1: line 118
	at Msvs, C:\projects\cef-binary-5r1rw\build.ps1: line 378
	at VSX, C:\projects\cef-binary-5r1rw\build.ps1: line 454
	at <ScriptBlock>, C:\projects\cef-binary-5r1rw\build.ps1: line 925
	at <ScriptBlock>, <No file>: line 1

This is probably the same issue as described here (Path environment variable is becoming too long as vcvarsall.bat always appends to it).
In that case, maybe it will work if we cache the original value of the Path, Lib, LibPath, Include environment variables, and reset them after the Msvs call is complete. What do you think?

The build failed when trying to build for x86 with v140 toolchain (but the arm64 build with v141 toolchain apparently succeeded):

Looks promising though 👍

In that case, maybe it will work if we cache the original value of the Path, Lib, LibPath, Include environment variables, and reset them after the Msvs call is complete. What do you think?

Happy to try that. Quick search and I see plenty of people attempting to reset the environment. We could potentially spawn a VS developer tools window for each build, they'd be isolated, lot more work involved though.