List/TupleBuiltins: fix __eq__ and __neq__ fallbacks

Author: cosminbasca

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/list/ListBuiltins.java

@@ -1061,8 +1061,8 @@ boolean doPListObjectStorage(VirtualFrame frame, PList left, PList right,
 
         @Fallback
         @SuppressWarnings("unused")
-        boolean doOther(Object left, Object right) {
-            return false;
+        Object doOther(Object left, Object right) {
+            return PNotImplemented.NOT_IMPLEMENTED;
         }
     }
 
@@ -1078,8 +1078,8 @@ boolean doPList(VirtualFrame frame, PList left, PList right,
 
         @Fallback
         @SuppressWarnings("unused")
-        boolean doOther(Object left, Object right) {
-            return true;
+        PNotImplemented doOther(Object left, Object right) {
+            return PNotImplemented.NOT_IMPLEMENTED;
         }
     }
 

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/tuple/TupleBuiltins.java

@@ -417,8 +417,8 @@ boolean doPTuple(VirtualFrame frame, PTuple left, PTuple right,
 
         @Fallback
         @SuppressWarnings("unused")
-        boolean doOther(Object left, Object right) {
-            return true;
+        PNotImplemented doOther(Object left, Object right) {
+            return PNotImplemented.NOT_IMPLEMENTED;
         }
     }