Summary:
Provides facilities to model the C++ conversion rules without the AST.
The introduced representation can be stored in the index and used to
implement type-based ranking improvements for index-based completions.
Reviewers: sammccall, ioeric
Reviewed By: sammccall
Subscribers: malaperle, mgorny, MaskRay, jkorous, arphaman, kadircet, cfe-commits
Differential Revision: https://reviews.llvm.org/D52273
llvm-svn: 347559