Bug 1351488 - Baldr: atomically ref-count ShareableBase (r=lth)

MozReview-Commit-ID: J8Ak5GxGmtd

--HG--
extra : rebase_source : 569a6ffc7d4ac58ed1b025a0399fbcf12711eea4

js/src/wasm/WasmTypes.h

@@ -145,7 +145,7 @@ typedef Vector<Type, 0, SystemAllocPolicy> VectorName;
 // about:memory stats.
 
 template <class T>
-struct ShareableBase : RefCounted<T>
+struct ShareableBase : AtomicRefCounted<T>
 {
     using SeenSet = HashSet<const T*, DefaultHasher<const T*>, SystemAllocPolicy>;