Change reference queue type parameter to PMemoryView

Author: msimacek

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/memoryview/BufferReference.java

@@ -43,11 +43,11 @@
 import java.lang.ref.PhantomReference;
 import java.lang.ref.ReferenceQueue;
 
-class BufferReference extends PhantomReference<Object> {
+class BufferReference extends PhantomReference<PMemoryView> {
     private final ManagedBuffer managedBuffer;
     private boolean released;
 
-    public BufferReference(Object referent, ManagedBuffer managedBuffer, ReferenceQueue<? super Object> q) {
+    public BufferReference(PMemoryView referent, ManagedBuffer managedBuffer, ReferenceQueue<PMemoryView> q) {
         super(referent, q);
         assert managedBuffer != null;
         managedBuffer.incrementExports();

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/memoryview/MemoryViewBuiltins.java

@@ -154,7 +154,7 @@ public void postInitialize(PythonCore core) {
         MemoryViewNodes.BufferReferences bufferReferences = new MemoryViewNodes.BufferReferences();
         core.lookupType(PythonBuiltinClassType.PMemoryView).setAttribute(bufferReferencesKey, bufferReferences);
         core.getContext().registerAsyncAction(() -> {
-            Reference<?> reference = null;
+            Reference<? extends PMemoryView> reference = null;
             try {
                 reference = bufferReferences.queue.remove();
             } catch (InterruptedException e) {

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/memoryview/MemoryViewNodes.java

@@ -996,7 +996,7 @@ static BufferReferences getRefs(@CachedContext(PythonLanguage.class) PythonConte
     }
 
     public static class BufferReferences {
-        public final ReferenceQueue<Object> queue = new ReferenceQueue<>();
+        public final ReferenceQueue<PMemoryView> queue = new ReferenceQueue<>();
         public final Set<BufferReference> set = new HashSet<>();
     }
 }