Put the type inference on calls with self types under the compiler flag

compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/inference/components/ConstraintInjector.kt

@@ -21,7 +21,7 @@ import kotlin.math.max
 class ConstraintInjector(
     val constraintIncorporator: ConstraintIncorporator,
     val typeApproximator: AbstractTypeApproximator,
-    private val languageVersionSettings: LanguageVersionSettings,
+    val languageVersionSettings: LanguageVersionSettings,
 ) {
     private val ALLOWED_DEPTH_DELTA_FOR_INCORPORATION = 1
 

compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/inference/components/ResultTypeResolver.kt

@@ -5,6 +5,8 @@
 
 package org.jetbrains.kotlin.resolve.calls.inference.components
 
+import org.jetbrains.kotlin.config.LanguageFeature
+import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.resolve.calls.NewCommonSuperTypeCalculator
 import org.jetbrains.kotlin.resolve.calls.inference.components.TypeVariableDirectionCalculator.ResolveDirection
 import org.jetbrains.kotlin.resolve.calls.inference.hasDeclaredUpperBoundSelfTypes
@@ -16,7 +18,8 @@ import org.jetbrains.kotlin.types.model.*
 
 class ResultTypeResolver(
     val typeApproximator: AbstractTypeApproximator,
-    val trivialConstraintTypeInferenceOracle: TrivialConstraintTypeInferenceOracle
+    val trivialConstraintTypeInferenceOracle: TrivialConstraintTypeInferenceOracle,
+    private val languageVersionSettings: LanguageVersionSettings
 ) {
     interface Context : TypeSystemInferenceExtensionContext {
         fun isProperType(type: KotlinTypeMarker): Boolean
@@ -211,8 +214,11 @@ class ResultTypeResolver(
     }
 
     private fun Context.findSuperType(variableWithConstraints: VariableWithConstraints): KotlinTypeMarker? {
+        val isTypeInferenceForSelfTypesSupported =
+            languageVersionSettings.supportsFeature(LanguageFeature.TypeInferenceOnCallsWithSelfTypes)
         val upperConstraints = variableWithConstraints.constraints.filter {
-            it.kind == ConstraintKind.UPPER && (hasDeclaredUpperBoundSelfTypes(it) || isProperTypeForFixation(it.type))
+            it.kind == ConstraintKind.UPPER
+                    && ((isTypeInferenceForSelfTypesSupported && hasDeclaredUpperBoundSelfTypes(it)) || isProperTypeForFixation(it.type))
         }
         if (upperConstraints.isNotEmpty()) {
             val intersectionUpperType = intersectTypes(upperConstraints.map { it.type })

compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/inference/components/VariableFixationFinder.kt

@@ -57,13 +57,17 @@ class VariableFixationFinder(
     private val inferenceCompatibilityModeEnabled: Boolean
         get() = languageVersionSettings.supportsFeature(LanguageFeature.InferenceCompatibility)
 
+    private val isTypeInferenceForSelfTypesSupported: Boolean
+        get() = languageVersionSettings.supportsFeature(LanguageFeature.TypeInferenceOnCallsWithSelfTypes)
+
     private fun Context.getTypeVariableReadiness(
         variable: TypeConstructorMarker,
         dependencyProvider: TypeVariableDependencyInformationProvider,
     ): TypeVariableFixationReadiness = when {
         !notFixedTypeVariables.contains(variable) ||
                 dependencyProvider.isVariableRelatedToTopLevelType(variable) -> TypeVariableFixationReadiness.FORBIDDEN
-        hasDeclaredUpperBoundSelfTypes(variable) -> TypeVariableFixationReadiness.READY_FOR_FIXATION_DECLARED_UPPER_BOUND_WITH_SELF_TYPES
+        isTypeInferenceForSelfTypesSupported && hasDeclaredUpperBoundSelfTypes(variable) ->
+            TypeVariableFixationReadiness.READY_FOR_FIXATION_DECLARED_UPPER_BOUND_WITH_SELF_TYPES
         !variableHasProperArgumentConstraints(variable) -> TypeVariableFixationReadiness.WITHOUT_PROPER_ARGUMENT_CONSTRAINT
         hasDependencyToOtherTypeVariables(variable) -> TypeVariableFixationReadiness.WITH_COMPLEX_DEPENDENCY
         variableHasTrivialOrNonProperConstraints(variable) -> TypeVariableFixationReadiness.WITH_TRIVIAL_OR_NON_PROPER_CONSTRAINTS

compiler/resolution.common/src/org/jetbrains/kotlin/types/AbstractTypeApproximator.kt

@@ -406,7 +406,9 @@ abstract class AbstractTypeApproximator(
 
             val argumentTypeConstructor = argument.getType().typeConstructor()
 
-            if (argumentTypeConstructor is TypeVariableTypeConstructorMarker && conf.selfTypesWithTypeVariablesToCapturedStarProjection) {
+            val isTypeInferenceForSelfTypesSupported =
+                languageVersionSettings.supportsFeature(LanguageFeature.TypeInferenceOnCallsWithSelfTypes)
+            if (isTypeInferenceForSelfTypesSupported && argumentTypeConstructor is TypeVariableTypeConstructorMarker && conf.selfTypesWithTypeVariablesToCapturedStarProjection) {
                 // If we have Self<TypeVariable(T)> where T is bounded by Self<T>, we approximate it to CapturedType(*) to satisfy constraints
                 if (argumentTypeConstructor.typeParameter?.hasRecursiveBounds(type.typeConstructor()) == true) {
                     return createCapturedStarProjectionForSelfType(argumentTypeConstructor, type)