[wasm] Add back oxford comma

The comma was removed as part of this CL: https://crrev.com/c/1355144
But layout tests rely on this: https://crrev.com/c/1372232
Thus add it back.

R=mslekova@chromium.org
CC=ahaas@chromium.org, ssauleau@igalia.com

Change-Id: I522cc9b448e5cf046074bf635bd9fc60ccf64795
Reviewed-on: https://chromium-review.googlesource.com/c/1373549Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58178}

src/wasm/wasm-js.cc

@@ -1128,10 +1128,11 @@ void WebAssemblyGlobal(const v8::FunctionCallbackInfo<v8::Value>& args) {
     } else {
       if (enabled_features.bigint) {
         thrower.TypeError(
-            "Descriptor property 'value' must be 'i32', 'i64', 'f32' or 'f64'");
+            "Descriptor property 'value' must be 'i32', 'i64', 'f32', or "
+            "'f64'");
       } else {
         thrower.TypeError(
-            "Descriptor property 'value' must be 'i32', 'f32' or 'f64'");
+            "Descriptor property 'value' must be 'i32', 'f32', or 'f64'");
       }
 
       return;