fixup! Runtime: normalize nan when hashing floats

Author: hhugo

runtime/js/hash.js

@@ -54,7 +54,9 @@ function caml_hash_mix_float(hash, v0) {
     l = 0x00000001;
   } else if (h === (0x80000000 | 0) && l === 0) {
     /* Normalize -0 into +0 */
-    h = 1;
+    // This code path is not used by caml_hash because 0 and -0 look
+    // like integers
+    h = 0;
   }
   hash = caml_hash_mix_int(hash, l);
   hash = caml_hash_mix_int(hash, h);