[clang][driver] Print compilation phases with indentation.

Reviewers: tra, sfantao, echristo

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69124

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@375310 91177308-0d34-0410-b5e6-96231b3b80d8