[PM] Completely remove support for explicit 'require' methods on the
AnalysisManager. All this method did was assert something and we have
a perfectly good way to trigger that assert from the query path.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194947 91177308-0d34-0410-b5e6-96231b3b80d8