Light class codegen: all objects are considered static

Simplify code handling access flag computation
Fix a problem where kotlin nested object wasn't producing a nested light class

compiler/testData/codegen/light-analysis/reflection/modifiers/classes.txt

@@ -41,7 +41,7 @@ public final class S/InnerClass {
 }
 
 @kotlin.Metadata
-public final class S/NonCompanionObject {
+public final static class S/NonCompanionObject {
     public final static field INSTANCE: S.NonCompanionObject
     inner class S/NonCompanionObject
     private method <init>(): void