[wasm] Fix WasmInstanceObject::GetGlobalBufferAndIndex

Fixing an issue in WasmInstanceObject::GetGlobalBufferAndIndex.

Bug: v8:13309
Change-Id: I52e65c109e43ce0300513604e71e587e1949f70a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3907666Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Samuel Groß <saelo@chromium.org>
Commit-Queue: Paolo Severini <paolosev@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#83345}

src/wasm/wasm-objects.cc

@@ -1501,7 +1501,8 @@ WasmInstanceObject::GetGlobalBufferAndIndex(Handle<WasmInstanceObject> instance,
         FixedArray::cast(
             instance->imported_mutable_globals_buffers().get(global.index)),
         isolate);
-    Address idx = instance->imported_mutable_globals().get(global.index);
+    Address idx = instance->imported_mutable_globals().get_int(
+        global.index * kSystemPointerSize);
     DCHECK_LE(idx, std::numeric_limits<uint32_t>::max());
     return {buffer, static_cast<uint32_t>(idx)};
   }