Introduce a specific representation for the ambiguous implicit conversion
sequence.  Lots of small relevant changes.  Fixes some serious problems with
ambiguous conversions;  also possibly improves associated diagnostics.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@93214 91177308-0d34-0410-b5e6-96231b3b80d8
10 files changed