AST: add missing ObjC extensions to MS style name decoration

Add support for encoding type arguments for lightweight generics in
Objective-C++ mode.  Additionally, add support for the `__kindof` modifier.
This should complete the coverage of the ObjC extensions that clang currently
supports under the MS style name decoration scheme.

This is implemented similar to the Objective-C lifetime qualifiers decoration:
a template specialization in the `__ObjC` namespace so that we can interoperate
with Microsoft's tools as well as ensure that we do not accidentally collide
with new features in the Microsoft implementation.

Since the `__kindof` appertains to the type and not the pointer, we apply the
template specialization to the underlying type instead of the pointer type.

Unfortunately, until D52581 is resolved, the generated name is not really
compatible with the MS tools as well as breaks interoperability with
Objective-C++ and C++.

This resolves PR37754!

llvm-svn: 343338