Can we have adaptive peephole optimization back?

Hi devs, I believe that we should have adaptive peephole optimization back. I believe that this should not be combined with -opt_speed, but should be a separate option, -opt_peephole, or should be implemented as a client. I believe that peephole optimization should always be performed after the -opt_speed inlining, if -opt_speed is passed, since we want to follow the libminecraft inline-then-optimize concept. Also, if you guys over-estimate compiler optimizations, then it's also possible for clients to generate inefficient code as well, and inlining opens up more opportunities for peephole optimization (e.g how about register allocation/stack optimization/whatever you call it after you inlined the unconditional branch/method call?).

[here's a link to a video about libminecraft's advanced-technology whole-program optimization](https://www.youtube.com/watch?v=tONR_7L7x80)