[NI] Get rid of FE 1.0 types in AbstractTypeApproximator

core/compiler.common/src/org/jetbrains/kotlin/types/model/TypeSystemContext.kt

@@ -28,6 +28,8 @@ interface TypeVariableTypeConstructorMarker : TypeConstructorMarker
 
 interface CapturedTypeConstructorMarker : TypeConstructorMarker
 
+interface IntersectionTypeConstructorMarker : TypeConstructorMarker
+
 interface TypeSubstitutorMarker
 
 
@@ -174,8 +176,12 @@ interface TypeSystemInferenceExtensionContext : TypeSystemContext, TypeSystemBui
         secondCandidate: KotlinTypeMarker
     ): KotlinTypeMarker
 
+    fun KotlinTypeMarker.isSpecial(): Boolean
+
     fun TypeConstructorMarker.isTypeVariable(): Boolean
     fun TypeVariableTypeConstructorMarker.isContainedInInvariantOrContravariantPositions(): Boolean
+
+    fun KotlinTypeMarker.isSignedOrUnsignedNumberType(): Boolean
 }
 
 
@@ -202,6 +208,9 @@ interface TypeSystemContext : TypeSystemOptimizationContext {
 
     fun SimpleTypeMarker.asDefinitelyNotNullType(): DefinitelyNotNullTypeMarker?
     fun SimpleTypeMarker.isMarkedNullable(): Boolean
+    fun KotlinTypeMarker.isMarkedNullable(): Boolean =
+        this is SimpleTypeMarker && isMarkedNullable()
+
     fun SimpleTypeMarker.withNullability(nullable: Boolean): SimpleTypeMarker
     fun SimpleTypeMarker.typeConstructor(): TypeConstructorMarker
 
@@ -323,7 +332,7 @@ interface TypeSystemContext : TypeSystemOptimizationContext {
     fun intersectTypes(types: List<KotlinTypeMarker>): KotlinTypeMarker
     fun intersectTypes(types: List<SimpleTypeMarker>): SimpleTypeMarker
 
-    fun KotlinTypeMarker.isSimpleType() = asSimpleType() != null
+    fun KotlinTypeMarker.isSimpleType(): Boolean = asSimpleType() != null
 
     fun prepareType(type: KotlinTypeMarker): KotlinTypeMarker
 

core/descriptors/src/org/jetbrains/kotlin/types/IntersectionTypeConstructor.kt

@@ -23,10 +23,11 @@ import org.jetbrains.kotlin.descriptors.annotations.Annotations
 import org.jetbrains.kotlin.resolve.scopes.MemberScope
 import org.jetbrains.kotlin.resolve.scopes.TypeIntersectionScope
 import org.jetbrains.kotlin.types.checker.KotlinTypeRefiner
+import org.jetbrains.kotlin.types.model.IntersectionTypeConstructorMarker
 import org.jetbrains.kotlin.types.refinement.TypeRefinement
 import java.util.*
 
-class IntersectionTypeConstructor(typesToIntersect: Collection<KotlinType>) : TypeConstructor {
+class IntersectionTypeConstructor(typesToIntersect: Collection<KotlinType>) : TypeConstructor, IntersectionTypeConstructorMarker {
     private var alternative: KotlinType? = null
 
     private constructor(

core/descriptors/src/org/jetbrains/kotlin/types/TypeSystemCommonBackendContext.kt

@@ -36,9 +36,6 @@ interface TypeSystemCommonBackendContext : TypeSystemContext {
     fun TypeParameterMarker.getRepresentativeUpperBound(): KotlinTypeMarker
     fun KotlinTypeMarker.getSubstitutedUnderlyingType(): KotlinTypeMarker?
 
-    fun KotlinTypeMarker.isMarkedNullable(): Boolean =
-        this is SimpleTypeMarker && isMarkedNullable()
-
     fun KotlinTypeMarker.makeNullable(): KotlinTypeMarker =
         asSimpleType()?.withNullability(true) ?: this
 

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

@@ -6,8 +6,8 @@
 package org.jetbrains.kotlin.types.checker
 
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
-import org.jetbrains.kotlin.builtins.StandardNames.FqNames
 import org.jetbrains.kotlin.builtins.PrimitiveType
+import org.jetbrains.kotlin.builtins.StandardNames.FqNames
 import org.jetbrains.kotlin.builtins.isBuiltinFunctionalTypeOrSubtype
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
@@ -31,6 +31,7 @@ import org.jetbrains.kotlin.types.typeUtil.representativeUpperBound
 import org.jetbrains.kotlin.utils.addToStdlib.safeAs
 import kotlin.contracts.ExperimentalContracts
 import kotlin.contracts.contract
+import org.jetbrains.kotlin.types.typeUtil.isSignedOrUnsignedNumberType as classicIsSignedOrUnsignedNumberType
 
 interface ClassicTypeSystemContext : TypeSystemInferenceExtensionContext, TypeSystemCommonBackendContext {
     override fun TypeConstructorMarker.isDenotable(): Boolean {
@@ -517,6 +518,11 @@ interface ClassicTypeSystemContext : TypeSystemInferenceExtensionContext, TypeSy
         errorSupportedOnlyInTypeInference()
     }
 
+    override fun KotlinTypeMarker.isSpecial(): Boolean {
+        require(this is KotlinType)
+        return this is TypeUtils.SpecialType
+    }
+
     override fun TypeConstructorMarker.isTypeVariable(): Boolean {
         errorSupportedOnlyInTypeInference()
     }
@@ -525,6 +531,11 @@ interface ClassicTypeSystemContext : TypeSystemInferenceExtensionContext, TypeSy
         errorSupportedOnlyInTypeInference()
     }
 
+    override fun KotlinTypeMarker.isSignedOrUnsignedNumberType(): Boolean {
+        require(this is KotlinType)
+        return classicIsSignedOrUnsignedNumberType()
+    }
+
     override fun findCommonIntegerLiteralTypesSuperType(explicitSupertypes: List<SimpleTypeMarker>): SimpleTypeMarker? {
         @Suppress("UNCHECKED_CAST")
         explicitSupertypes as List<SimpleType>