This patch flattens both sel-sched-dump.h and sel-sched-ir.h. Both these 
files end up including cfgloop.h, so in preparation for flattening 
cfgloop.h, flatten these.  Note they actually have only a small effect 
on what includes them.

Bootstraps from scratch on x86_64-unknown-linux-gnu with no new 
regressions. Also compiles all the files in config-list.mk.