Light classes: handle broken context in case of supertype delegation

This lead to an exception being thrown frequently
Proper fix would be to prevent binding context from being corrupted
Known cases are hard to debug/reproduce

 #EA-101081 Fixed

compiler/backend-common/src/org/jetbrains/kotlin/backend/common/CodegenUtil.kt

@@ -98,9 +98,8 @@ object CodegenUtil {
     @JvmStatic
     fun getSuperClassBySuperTypeListEntry(specifier: KtSuperTypeListEntry, bindingContext: BindingContext): ClassDescriptor? {
         val superType = bindingContext.get(BindingContext.TYPE, specifier.typeReference!!)
-                        ?: error("superType should not be null: ${specifier.text}")
 
-        return superType.constructor.declarationDescriptor as? ClassDescriptor
+        return superType?.constructor?.declarationDescriptor as? ClassDescriptor
     }
 
     @JvmStatic