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

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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@241845 91177308-0d34-0410-b5e6-96231b3b80d8