Provide a method for generating deterministic IDs for pointers allocated in BumpPtrAllocator
Provide a method for generating deterministic IDs for pointers allocated in BumpPtrAllocator

Differential Revision: https://reviews.llvm.org/D51393

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@341599 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 0c89ce389bde399e9ea1a3bf98446adb33e6168a)

apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm