Topics in live kernel patching

This is... ah, impractical, because there is really no boundary between 'optimizations' and 'compilation': there are just a long series of transformations that convert the source into the output. Some of these transformations are optional, but you surely don't want to log all of those (and in how much detail? many optimizations change their output depending on which optimizations have run before them...). As a first step, the code added for LTO which records the state of the compiler (incl compilation flags) into the (LTO streamer) output might be a good start: combine that with -frandom-seed= and you can pretty much guarantee reproducible output between runs, which is probably the best you can hope for here.