Inliner: use offset in xml replay

Inliner: use offset in xml replay

Replay needs the ability to distinguish among multiple calls to the same
callee. The IL offset of the call site can be used for this, so start
checking for it during replay.

Note there is subsequent follow-up work to ensure that we actually track
offsets for calls.

Refactor the way the ReplayPolicy gets notified of the current inline
context (and the IL offset of the call). Instead of trying to pass
this information as arguments to the factory method that creates
policies, add special notifications for this information that only the
ReplayPolicy will act upon.

Commit migrated from https://github.com/dotnet/coreclr/commit/be9d889b084099797dfcf019b2820433558dbec9