Move ChainedIncludesSource into the Frontend library. This never really
belonged in the Serialization library, it's setting up a compilation,
not just deserializing.

This should fix PR11512, making Serialization actually be layered below
Frontend, a long standing layering violation in Clang.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@146233 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed