(e.g. due to a broken template argument) following template parameters.

Fixes rdar://problem/8254267

llvm-svn: 109853

definition, we're likely going to end up breaking the invariants of
the template system, e.g., that the depths of template parameter lists
match up with the nesting template of the template. So, make sure we
mark such ill-formed declarations as invalid or don't even build them
at all.

llvm-svn: 108372