Improve compiler cli args (#22509)

* .

* Fix cli args out of range with descriptive error instead of crash

* #22509 (comment)

compiler/commands.nim

@@ -891,15 +891,19 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
  defineSymbol(conf.symbols, "nodejs")
  of "maxloopiterationsvm":
  expectArg(conf, switch, arg, pass, info)
- conf.maxLoopIterationsVM = parseInt(arg)
+ var value: int = 10_000_000
+ discard parseSaturatedNatural(arg, value)
+ if not value > 0: localError(conf, info, "maxLoopIterationsVM must be a positive integer greater than zero")
+ conf.maxLoopIterationsVM = value
  of "errormax":
  expectArg(conf, switch, arg, pass, info)
  # Note: `nim check` (etc) can overwrite this.
  # `0` is meaningless, give it a useful meaning as in clang's -ferror-limit
  # If user doesn't set this flag and the code doesn't either, it'd
  # have the same effect as errorMax = 1
- let ret = parseInt(arg)
- conf.errorMax = if ret == 0: high(int) else: ret
+ var value: int = 0
+ discard parseSaturatedNatural(arg, value)
+ conf.errorMax = if value == 0: high(int) else: value
  of "verbosity":
  expectArg(conf, switch, arg, pass, info)
  let verbosity = parseInt(arg)
@@ -913,7 +917,9 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
  conf.mainPackageNotes = conf.notes
  of "parallelbuild":
  expectArg(conf, switch, arg, pass, info)
- conf.numberOfProcessors = parseInt(arg)
+ var value: int = 0
+ discard parseSaturatedNatural(arg, value)
+ conf.numberOfProcessors = value
  of "version", "v":
  expectNoArg(conf, switch, arg, pass, info)
  writeVersionInfo(conf, pass)