Fix unjustified descriptorToDeclaration in bridge codegen

Delegated and synthesized members don't usually have a declaration as well as
fake overrides

compiler/testData/codegen/boxWithJava/delegation/delegationAndInheritanceFromJava.java

@@ -0,0 +1,7 @@
+import java.util.Set;
+
+public class delegationAndInheritanceFromJava {
+    public interface A extends Set<String> {}
+
+    public interface B extends Set<String> {}
+}