depends on the IR infrastructure, there is no sense in it being off in
Support land.
This is in preparation to start working to expand InstVisitor into more
special-purpose visitors that are still generic and can be re-used
across different passes. The expansion will go into the Analylis tree
though as nothing in VMCore needs it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168972 91177308-0d34-0410-b5e6-96231b3b80d8
