Add example where some numerical ad hoc optimization kicks in.

Author: cristianoc

jscomp/test/variantsMatching.js

@@ -1,7 +1,11 @@
 'use strict';
 
 
-function foo(x) {
+function toEnum(x) {
+  return x;
+}
+
+function toString(x) {
   switch (x) {
     case /* A */0 :
         return "A";
@@ -114,7 +118,8 @@ function third2(l) {
   }
 }
 
-exports.foo = foo;
+exports.toEnum = toEnum;
+exports.toString = toString;
 exports.bar = bar;
 exports.and_ = and_;
 exports.id = id;

jscomp/test/variantsMatching.res

@@ -1,6 +1,15 @@
 type t = A | B | C | D | E
 
-let foo = x =>
+let toEnum = x =>
+  switch x {
+  | A => 0
+  | B => 1
+  | C => 2
+  | D => 3
+  | E => 4
+  }
+
+let toString = x =>
   switch x {
   | A => "A"
   | B => "B"