Revert r267784, r267824 and r267830.

It makes compiler-rt tests fail if the gold plugin is enabled.

Revert "Rework interface for bitset-using features to use a notion of LTO visibility."
Revert "Driver: only produce CFI -fvisibility= error when compiling."
Revert "clang/test/CodeGenCXX/cfi-blacklist.cpp: Exclude ms targets. They would be non-cfi."

llvm-svn: 267871