Add LoadOp back to emscripten gen bits headers

Change-Id: Iacfceb9785ff04f3b4774cc3eeb4d4c4d1f46591
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/88466
Auto-Submit: Shrek Shao <shrekshao@google.com>
Commit-Queue: Kai Ninomiya <kainino@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Shrek Shao <shrekshao@google.com>
diff --git a/dawn.json b/dawn.json
index 5463b92..b0aa232 100644
--- a/dawn.json
+++ b/dawn.json
@@ -1465,7 +1465,6 @@
     },
     "load op": {
         "category": "enum",
-        "emscripten_no_enum_table": true,
         "values": [
             {"value": 0, "name": "undefined", "jsrepr": "undefined"},
             {"value": 1, "name": "clear"},