Bug 1332691: Skip conversions.wast.js.html for unexpected successes on x86; r=bustage

testing/web-platform/mozilla/meta/wasm/conversions.wast.js.html.ini

@@ -1,4 +1,5 @@
 [conversions.wast.js.html]
+  disabled: https://bugzilla.mozilla.org/show_bug.cgi?id=1336139
   type: testharness
   [#499 A wast test that runs without any special assertion.]
     expected: FAIL