Add some infrastructure for dealing with expressions of 'placeholder' type,
i.e. expressions with an internally-convenient type which should not be
appearing in generally valid, complete ASTs.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@116281 91177308-0d34-0410-b5e6-96231b3b80d8
10 files changed