Remove all type system dependent methods from TypeCheckerState

core/descriptors/src/org/jetbrains/kotlin/resolve/OverridingUtilTypeSystemContext.kt

@@ -32,7 +32,6 @@ class OverridingUtilTypeSystemContext(
         return ClassicTypeCheckerState(
             errorTypesEqualToAnything,
             stubTypesEqualToAnything,
-            allowedTypeVariable = true,
             kotlinTypeRefiner,
             typeSystemContext = this
         )

core/descriptors/src/org/jetbrains/kotlin/types/checker/ClassicTypeCheckerState.kt

@@ -23,7 +23,6 @@ import org.jetbrains.kotlin.types.model.SimpleTypeMarker
 open class ClassicTypeCheckerState(
     val errorTypeEqualsToAnything: Boolean,
     val stubTypeEqualsToAnything: Boolean = true,
-    val allowedTypeVariable: Boolean = true,
     override val kotlinTypeRefiner: KotlinTypeRefiner = KotlinTypeRefiner.Default,
     override val kotlinTypePreparator: KotlinTypePreparator = KotlinTypePreparator.Default,
     override val typeSystemContext: ClassicTypeSystemContext = SimpleClassicTypeSystemContext
@@ -34,29 +33,6 @@ open class ClassicTypeCheckerState(
     override val isStubTypeEqualsToAnything: Boolean
         get() = stubTypeEqualsToAnything
 
-    override fun substitutionSupertypePolicy(type: SimpleTypeMarker): SupertypesPolicy.DoCustomTransform {
-        return typeSystemContext.classicSubstitutionSupertypePolicy(type)
-    }
-
-    override val KotlinTypeMarker.isAllowedTypeVariable: Boolean get() = this is UnwrappedType && allowedTypeVariable && constructor is NewTypeVariableConstructor
-
-    companion object {
-        fun ClassicTypeSystemContext.classicSubstitutionSupertypePolicy(type: SimpleTypeMarker): SupertypesPolicy.DoCustomTransform {
-            require(type is SimpleType, type::errorMessage)
-            val substitutor = TypeConstructorSubstitution.create(type).buildSubstitutor()
-
-            return object : SupertypesPolicy.DoCustomTransform() {
-                override fun transformType(state: TypeCheckerState, type: KotlinTypeMarker): SimpleTypeMarker {
-                    return substitutor.safeSubstitute(
-                        type.lowerBoundIfFlexible() as KotlinType,
-                        Variance.INVARIANT
-                    ).asSimpleType()!!
-                }
-            }
-        }
-    }
-}
-
-private fun Any.errorMessage(): String {
-    return "ClassicTypeCheckerContext couldn't handle ${this::class} $this"
+    override val allowedTypeVariable: Boolean
+        get() = true
 }

core/descriptors/src/org/jetbrains/kotlin/types/checker/ClassicTypeSystemContext.kt

@@ -788,6 +788,24 @@ interface ClassicTypeSystemContext : TypeSystemInferenceExtensionContext, TypeSy
         } else {
             createFlexibleType(this, this.withNullability(true))
         }
+
+    override fun substitutionSupertypePolicy(type: SimpleTypeMarker): TypeCheckerState.SupertypesPolicy {
+        require(type is SimpleType, type::errorMessage)
+        val substitutor = TypeConstructorSubstitution.create(type).buildSubstitutor()
+
+        return object : TypeCheckerState.SupertypesPolicy.DoCustomTransform() {
+            override fun transformType(state: TypeCheckerState, type: KotlinTypeMarker): SimpleTypeMarker {
+                return substitutor.safeSubstitute(
+                    type.lowerBoundIfFlexible() as KotlinType,
+                    Variance.INVARIANT
+                ).asSimpleType()!!
+            }
+        }
+    }
+
+    override fun KotlinTypeMarker.isTypeVariableType(): Boolean {
+        return this is UnwrappedType && constructor is NewTypeVariableConstructor
+    }
 }
 
 fun TypeVariance.convertVariance(): Variance {