Refactor. Remove ConstraintPosition data duplication

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

@@ -43,7 +43,7 @@ class ConstraintInjector(
 
     fun addInitialSubtypeConstraint(c: Context, lowerType: KotlinTypeMarker, upperType: KotlinTypeMarker, position: ConstraintPosition) {
         val initialConstraint = InitialConstraint(lowerType, upperType, UPPER, position).also { c.addInitialConstraint(it) }
-        val typeCheckerState = TypeCheckerStateForConstraintInjector(c, IncorporationConstraintPosition(position, initialConstraint))
+        val typeCheckerState = TypeCheckerStateForConstraintInjector(c, IncorporationConstraintPosition(initialConstraint))
 
         updateAllowedTypeDepth(c, lowerType)
         updateAllowedTypeDepth(c, upperType)
@@ -69,7 +69,7 @@ class ConstraintInjector(
             else -> return
         }
         val initialConstraint = InitialConstraint(typeVariable, equalType, EQUALITY, position).also { c.addInitialConstraint(it) }
-        val typeCheckerState = TypeCheckerStateForConstraintInjector(c, IncorporationConstraintPosition(position, initialConstraint))
+        val typeCheckerState = TypeCheckerStateForConstraintInjector(c, IncorporationConstraintPosition(initialConstraint))
 
         // We add constraints like `T? == Foo!` in the old way
         if (!typeVariable.isSimpleType() || typeVariable.isMarkedNullable()) {

compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/inference/model/ConstraintPositionAndErrors.kt

@@ -77,10 +77,11 @@ open class DelegatedPropertyConstraintPosition<T>(val topLevelCall: T) : Constra
 }
 
 data class IncorporationConstraintPosition(
-    val from: ConstraintPosition,
     val initialConstraint: InitialConstraint,
     var isFromDeclaredUpperBound: Boolean = false
 ) : ConstraintPosition() {
+    val from: ConstraintPosition get() = initialConstraint.position
+
     override fun toString(): String = "Incorporate $initialConstraint from position $from"
 }