CFI: Emit correct bit set information if RTTI is disabled under MS ABI.

We were previously creating bit set entries at virtual table offset
sizeof(void*) unconditionally under the Microsoft C++ ABI. This is incorrect
if RTTI data is disabled; in that case the "address point" is at offset
0. This change modifies bit set emission to take into account whether RTTI
data is being emitted.

Also make a start on a blacklisting scheme for records.

Differential Revision: http://reviews.llvm.org/D11048

llvm-svn: 241845