[reanalyze] [bug] division_by_zero exception analysis should check constant denominators

repro:

let foo = (x: int) => {
  x / 10
}

reanalyze gives:

{
  "name": "Exception Analysis",
  "kind": "warning",
  "file": "Foo.res",
  "range": [20,4,20,7],
  "message": "foo might raise Division_by_zero (Foo.res:22:4) and is not annotated with @raises(Division_by_zero)",
  "annotate": { "line": 20, "character": 0, "text": "@raises(Division_by_zero)\n", "action": "Add @raises annotation"}
}

it's trivially clear that division by zero can't happen, and so reanalyze should not suggest the annotation.

Commencez dans le chemin d’analyse des exceptions de reanalyze qui signale Division_by_zero pour l’expression x / 10 affichée. Suivez la manière dont les valeurs du dénominateur sont classées, puis vérifiez qu’un dénominateur constant non nul ne produit plus l’avertissement d’annotation, tout en vous assurant que la reproduction de l’issue reste couverte.