todo: Building against an installed LLVM works

We only care about cmake and the buildbots test that it works.

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@205983 91177308-0d34-0410-b5e6-96231b3b80d8
www: Fix typo

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@205984 91177308-0d34-0410-b5e6-96231b3b80d8