In -ast-dump, only dump comments when dumping the actual Decl to which they
attach, rather than merging all comments on the declaration chain. This gives a
more faithful dump, and has the side benefit of unbreaking uses of dump() from
within AST deserialization (where the redeclaration chain may not be sane).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@182350 91177308-0d34-0410-b5e6-96231b3b80d8