Precompiled dependencies

• LLVM 10.0.0 (old)
• LLVM 15.0.3
• Qt 5.12.12

All for Visual Studio 2017 (and later). You can extract these packages in their own folder and then use the -DCMAKE_PREFIX_PATH=c:/path/to/llvm;c:/path/to/qt command line to build with them.