Libc++ fails to install on appveyor.

[Sebanisu]

Because of https://help.appveyor.com/discussions/problems/29137-failing-to-install-libc-on-ubuntu-2004
Cannot resolve this: #5

Some c++20 features are only in the libc++ and I cannot get appveyor to install it.

[Sebanisu]

I might need to use a different ubuntu image. like an older version or something.

[Sebanisu]

https://ci.appveyor.com/project/Sebanisu/toolslibrary/builds/38325435 I did get it past that point using Ubuntu 16.04 Xenial Xerus so I can update the yml and then see why it isn't compiling. Atleast I got past the can't find error. It's something else now. And I can work on that later.

[Sebanisu]

Okay, So random-test causes clang to crash... I dunno why. I am also missing linker commands. So I need to add the linker for libc++ to cmake.

[Sebanisu]

https://ci.appveyor.com/project/Sebanisu/toolslibrary/builds/38333464 tests are passing now. Minus the random-test.