Represent raw types in IR using a special type annotation

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

@@ -38,6 +38,9 @@ open class StubGeneratorExtensions {
     open val enhancedNullabilityAnnotationConstructor: IrConstructor?
         get() = null
 
+    open val rawTypeAnnotationConstructor: IrConstructor?
+        get() = null
+
     companion object {
         @JvmField
         val EMPTY = StubGeneratorExtensions()

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

@@ -208,6 +208,10 @@ class TypeTranslator(
             irAnnotations.addSpecialAnnotation(extensions.flexibleNullabilityAnnotationConstructor)
         }
 
+        if (flexibleType is RawType) {
+            irAnnotations.addSpecialAnnotation(extensions.rawTypeAnnotationConstructor)
+        }
+
         return irAnnotations
     }