Remove whitespace in operator literal declarations (issue #447)

[andrjohns]

Closes #447

[DavisVaughan]

Thanks, this does look like all of them.

Normally I'd resist changing things in fmt/, as that is 3rd party code we vendor. But it looks like (from looking at their repo) they have fixed this already, so when we do #400 we will just re-inherit the patches we are doing here.