[ms-cxxabi] Emit non-virtual member function pointers

Without any conversion, this is pretty straightforward.  Most of the
fields can be zeros.  The order is:

- field offset or pointer
- nonvirtual adjustment (for MI functions)
- vbptr offset (for unspecified)
- virtual adjustment offset (for virtual inheritance)

Differential Revision: http://llvm-reviews.chandlerc.com/D699

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180985 91177308-0d34-0410-b5e6-96231b3b80d8