testers needed for a boot cleanup patch

Hi,

I cleaned up locore.S a bit. I've tested it on two machines, but there
is a small risk it will break others. specifically emips, which is
already somewhat broken.

Would like more testing on:
- very old MIPS
- emips (I can't run Windows)
- others are also good

please try it out. Download this file:
http://coypu.sdf.org/20180124-locore.S
replace src/sys/arch/mips/mips/locore.S with it

Build a new kernel

If the following apply, try:
- doesn't blow up
- hardware floating point
- 64bit code (run 'vmstat', build with -mabi=64, may need -static
  because of other bugs)

Thanks!

(For the curious, the description and split up to individual commits is
here: http://coypu.sdf.org/locore-start/)