`nim check` doesn't work and should be replace by newly introduced `--errorMax:0` flag

[timotheecour]

see my PR that was recently merged : https://github.com/nim-lang/Nim/pull/9916

on posix: 
nim c --errorMax:0 -o:/dev/null main.nim
on windows:
nim c --errorMax:0 -o:null main.nim # need to double check that