Push nested-name-specifier source location information into

DependentNameTypeLoc. Teach the recursive AST visitor and libclang how to
walk DependentNameTypeLoc nodes.

Also, teach libclang about TypedefDecl source ranges, so that we get
those. The massive churn in test/Index/recursive-cxx-member-calls.cpp
is a good thing: we're annotating a lot more of this test correctly
now.

llvm-svn: 126729