Implement script instance capturing in script lowering

for regular classes only. Reimplementing the main behavior of the
old BE and implementing few cases on top of it.
#KT-19423 fixed

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/AdditionalIrUtils.kt

@@ -147,6 +147,7 @@ val IrDeclaration.isLocal: Boolean
             }
 
             if (current.isAnonymousObject) return true
+            if (current is IrScript || (current is IrClass && current.origin == IrDeclarationOrigin.SCRIPT_CLASS)) return true
 
             current = current.parent
         }