Emit aliases into the system image
- Put the interposer in llvm.compiler.used.
- Injecting the aliases after optimization:
Our multiversioning pass interacts badly with the llvm.compiler.used gvar.
Co-authored-by: Tim Besard <tim.besard@gmail.com>
Co-authored-by: Valentin Churavy <v.churavy@gmail.com>
