Fix a FIXME by not creating an invalid AST on erroneous input.  Also 
make diagnostic output in some other malformed cases significantly
more useful.  This fixes PR2708


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@55215 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed