Implement fallback case for 'PyType_IsSubtype'.

Author: fangerer

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/TruffleCextBuiltins.java

@@ -2042,10 +2042,11 @@ long doGeneric(Object n) {
 
     @Builtin(name = "PyType_IsSubtype", fixedNumOfPositionalArgs = 2)
     @GenerateNodeFactory
-    abstract static class PyType_IsSubtype extends PythonBuiltinNode {
+    abstract static class PyType_IsSubtype extends PythonBinaryBuiltinNode {
 
         @Child private IsSubtypeNode isSubtypeNode = IsSubtypeNode.create();
         @Child private CExtNodes.AsPythonObjectNode asPythonObjectNode = CExtNodes.AsPythonObjectNode.create();
+        @Child private CExtNodes.ToJavaNode toJavaNode;
 
         @Specialization(guards = {"a == cachedA", "b == cachedB"})
         int doCached(@SuppressWarnings("unused") PythonNativeWrapper a, @SuppressWarnings("unused") PythonNativeWrapper b,
@@ -2056,10 +2057,19 @@ int doCached(@SuppressWarnings("unused") PythonNativeWrapper a, @SuppressWarning
         }
 
         @Specialization(replaces = "doCached")
-        int doGeneric(PythonNativeWrapper a, PythonNativeWrapper b) {
+        int doUncached(PythonNativeWrapper a, PythonNativeWrapper b) {
             return isNativeSubtype(a, b);
         }
 
+        @Fallback
+        int doGeneric(Object a, Object b) {
+            if (toJavaNode == null) {
+                CompilerDirectives.transferToInterpreterAndInvalidate();
+                toJavaNode = insert(CExtNodes.ToJavaNode.create());
+            }
+            return isSubtypeNode.execute(toJavaNode.execute(a), toJavaNode.execute(b)) ? 1 : 0;
+        }
+
         protected int isNativeSubtype(PythonNativeWrapper a, PythonNativeWrapper b) {
             assert a instanceof PythonClassNativeWrapper || a instanceof PythonClassInitNativeWrapper;
             assert b instanceof PythonClassNativeWrapper || b instanceof PythonClassInitNativeWrapper;