DXC Compilation Fails on Linux but works on Windows

[aquagoose]

Calling IDxcCompiler.Compile() works on Windows, but fails on Linux.

I should also note that IDxcUtils.BuildArguments() also provides incorrect argument strings on Linux.

From working with low-level DXC myself I'm almost certain this is something to do with the differences between the way DXC is built on Windows vs Linux (it seems to use 4-byte chars on Linux)

I may look to fix this and PR the changes if I can get Vortice to compile on one of my machines!