Add support for DenseMap/DenseSet count and find using const pointers

Summary:
Similar to SmallPtrSet, this makes find and count work with both const
referneces and const pointers.

Reviewers: dblaikie

Subscribers: llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D30713

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297424 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed