Do not add extra 'this' parameter for TImpl's accessor

Fixes weird cases like super-call from a closure inside a trait with a required
class

compiler/backend/src/org/jetbrains/jet/codegen/state/JetTypeMapper.java

@@ -519,8 +519,6 @@ public class JetTypeMapper extends BindingTraceAware {
 
         signatureVisitor.writeParametersStart();
 
-        writeThisForAccessorIfNeeded(f, signatureVisitor);
-
         if (kind == OwnerKind.TRAIT_IMPL) {
             ClassDescriptor containingDeclaration = (ClassDescriptor) f.getContainingDeclaration();
             JetType jetType = CodegenUtil.getSuperClass(containingDeclaration);
@@ -534,6 +532,9 @@ public class JetTypeMapper extends BindingTraceAware {
             signatureVisitor.writeAsmType(type, jetType.isNullable());
             signatureVisitor.writeParameterTypeEnd();
         }
+        else {
+            writeThisForAccessorIfNeeded(f, signatureVisitor);
+        }
 
         if (receiverType != null) {
             signatureVisitor.writeParameterType(JvmMethodParameterKind.RECEIVER);