Remove Sema includes from Analysis code to fix layering

This moves a header-only class from Sema to Analysis and puts the option
check in Sema.

Patch by Chris Wailes!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188230 91177308-0d34-0410-b5e6-96231b3b80d8