[x86/SLH] Sink the return hardening into the main block-walk + hardening
code.

This consolidates all our hardening calls, and simplifies the code
a bit. It seems much more clear to handle all of these together.

No functionality changed here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337895 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed