libclang: Port CIndexer::getClangResourcesPath to PathV2. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183901 91177308-0d34-0410-b5e6-96231b3b80d8
libclang: Remove clang::RemapFiles, it's dead code.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183902 91177308-0d34-0410-b5e6-96231b3b80d8