Handle __class__ pathologies (#1540)

Author: BCSharp

Src/IronPython/Compiler/Ast/ClassDefinition.cs

@@ -128,6 +128,7 @@ internal override bool TryBindOuter(ScopeStatement from, PythonReference referen
             if (TryGetVariable(reference.Name, out variable)) {
                 if (variable.Kind is VariableKind.Global) {
                     AddReferencedGlobal(reference.Name);
+                    return variable;
                 } else if (variable.Kind is VariableKind.Local) {
                     // TODO: This results in doing a dictionary lookup to get/set the local,
                     // when it should probably be an uninitialized check / global lookup for gets

Src/IronPython/Runtime/Operations/PythonOps.cs

@@ -1498,7 +1498,7 @@ public static void InitializeForFinalization(CodeContext/*!*/ context, object ne
 
             // If __class__ is used, verify that it has been set
             if (vars._storage is RuntimeVariablesDictionaryStorage storage) {
-                int pos = Array.IndexOf(storage.Names, "__class__");
+                int pos = Array.IndexOf(storage.Names, "__class__", storage.NumFreeVars, storage.Names.Length - storage.NumFreeVars);
                 if (pos >= 0) {
                     ClosureCell classCell = storage.GetCell(pos);
                     if (!ReferenceEquals(classCell.Value, obj)) {

Src/IronPythonTest/Cases/CPythonCasesManifest.ini

@@ -887,7 +887,7 @@ Ignore=true
 Reason=ImportError: No module named _msi
 
 [CPython.test_super]
-Ignore=true
+Ignore=false # will have to be ignored again in 3.6
 
 [CPython.test_support]
 RunCondition=NOT $(IS_POSIX) # TODO: debug