Added calculateRangesAfterReplaments() to calculate affacted ranges in the new code.

Summary:
Added calculateRangesAfterReplaments() to calculate original ranges as well as
newly affacted ranges in the new code.

Reviewers: klimek, djasper

Subscribers: cfe-commits, klimek

Differential Revision: http://reviews.llvm.org/D21547

llvm-svn: 273290