update to match LLVM API change:

update to match LLVM API change:

Remove isPod() from DenseMapInfo, splitting it out to its own
isPodLike type trait.  This is a generally useful type trait for
more than just DenseMap, and we really care about whether something
acts like a pod, not whether it really is a pod.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@91422 91177308-0d34-0410-b5e6-96231b3b80d8