[PM] Move the LoopInfo analysis pointer into the InstCombiner class

[PM] Move the LoopInfo analysis pointer into the InstCombiner class
along with the other analyses.

The most obvious reason why is because eventually I need to separate out
the pass layer from the rest of the instcombiner. However, it is also
probably a compile time win as every query through the pass manager
layer is pretty slow these days.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226550 91177308-0d34-0410-b5e6-96231b3b80d8