There seems to be a modest improvement on some workloads:
```
$ time rg -co '\w+' sixteenth.txt
158520346
real 8.457
user 8.426
sys 0.020
maxmem 779 MB
faults 0
$ time rg-lto -co '\w+' sixteenth.txt
158520346
real 8.200
user 8.178
sys 0.012
maxmem 778 MB
faults 0
```
I've somewhat reversed course on my previous thoughts here. The
improvement isn't much, but the hit to compile times in CI isn't
terrible. Mostly I'm doing this out of "good sense," and I think it's
generally unlikely to make it more difficult for me to diagnose
performance problems. (Since I still use the default `release` profile
locally, since it's about an order of magnitude quicker to compile.)
Ref #325, Ref #413, Ref #1187, Ref #1255
4c953731c4