BUILD: reorder objects in the Makefile for faster builds

Splitting large files and changing includes has changed the per-file
build time. After a careful reordering based on build time, we're now
down to 5.8s at -O0 on the PC at -j8 and 2.4-2.6s on the farm at -j120.
Some room for at least one file name was left on each line to ease
future additions.
1 file changed