[llvm-config] Add minimal sanity tests for path options
[llvm-config] Add minimal sanity tests for path options

Add minimal tests that check whether path options do not fail and output
directories looking like expected. Requested in
https://reviews.llvm.org/rL291218.

Differential Revision: https://reviews.llvm.org/D28533

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@297807 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,apple/swift-llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm