Setup With LLILC Out Of LLVM Tree

In the getting started for windows directions are given on how to configure LLILC when the LLILC repository is placed in the LLVM/tools subdirectory. This page tells how to configure LLVM and LLILC when the LLILC workspace is separate from the LLVM workspace. This might be desirable, for example, if you want to have multiple LLILC workspaces (for working on multiple branches simultaneously) but want to share a single LLVM workspace and LLVM build.