Un-templatetize this method. It's definition is out of line in the .cpp file,

so that's not a valid thing to do at all. Instead, switch to a ValueDecl
argument, the template isn't really necessary here.

When handling the types explicitly in the code, it becomes awkward to cerate
the CXXBaseOrMemberInitializer object in so many places. Re-flow the code to
calculate the Init expression first, and then create the initializer. If this
is too gross, we can factor the init expression logic into helper functions,
but it's not past my threshold yet.

llvm-svn: 120997