FIR: Implement captured type substitution

compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/substitution/Substitutors.kt

@@ -61,7 +61,7 @@ abstract class AbstractConeSubstitutor(private val typeContext: ConeTypeContext)
                 if (it.lowerBound == it.upperBound) it.lowerBound
                 else it
             }
-            is ConeCapturedType -> return null
+            is ConeCapturedType -> return substituteCapturedType()
             is ConeDefinitelyNotNullType -> this.substituteOriginal()
             is ConeIntersectionType -> this.substituteIntersectedTypes()
             is ConeStubType -> return null
@@ -69,6 +69,24 @@ abstract class AbstractConeSubstitutor(private val typeContext: ConeTypeContext)
         }
     }
 
+    private fun ConeCapturedType.substituteCapturedType(): ConeCapturedType? {
+        val innerType = this.lowerType ?: this.constructor.projection.type
+        val substitutedInnerType = substituteOrNull(innerType) ?: return null
+        if (substitutedInnerType is ConeCapturedType) return substitutedInnerType
+        val substitutedSuperTypes =
+            this.constructor.supertypes?.map { substituteOrSelf(it) }
+
+        return ConeCapturedType(
+            captureStatus,
+            constructor = ConeCapturedTypeConstructor(
+                wrapProjection(constructor.projection, substitutedInnerType),
+                substitutedSuperTypes,
+                typeParameterMarker = constructor.typeParameterMarker
+            ),
+            lowerType = if (lowerType != null) substitutedInnerType else null
+        )
+    }
+
     private fun ConeIntersectionType.substituteIntersectedTypes(): ConeIntersectionType? {
         val substitutedTypes = ArrayList<ConeKotlinType>(intersectedTypes.size)
         var somethingIsSubstituted = false