[FIR] Add ConeKotlinTypeConflictingProjection, return it from substituteArgument instead of ConeStarProjection in appropriate cases, remove plus operator from ProjectionKind

compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeTypes.kt

@@ -15,16 +15,6 @@ import org.jetbrains.kotlin.utils.addToStdlib.foldMap
 
 enum class ProjectionKind {
     STAR, IN, OUT, INVARIANT;
-
-    operator fun plus(other: ProjectionKind): ProjectionKind {
-        return when {
-            this == other -> this
-            this == STAR || other == STAR -> STAR
-            this == INVARIANT -> other
-            other == INVARIANT -> this
-            else -> STAR
-        }
-    }
 }
 
 sealed class ConeTypeProjection : TypeArgumentMarker {
@@ -54,6 +44,11 @@ data class ConeKotlinTypeProjectionOut(override val type: ConeKotlinType) : Cone
         get() = ProjectionKind.OUT
 }
 
+data class ConeKotlinTypeConflictingProjection(override val type: ConeKotlinType) : ConeKotlinTypeProjection() {
+    override val kind: ProjectionKind
+        get() = ProjectionKind.INVARIANT
+}
+
 val ConeTypeProjection.type: ConeKotlinType?
     get() = when (this) {
         ConeStarProjection -> null

compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/TypeRenderer.kt

@@ -59,6 +59,7 @@ private fun ConeKotlinType.renderAttributes(): String {
 fun ConeTypeProjection.render(): String {
     return when (this) {
         ConeStarProjection -> "*"
+        is ConeKotlinTypeConflictingProjection -> "CONFLICTING-PROJECTION ${type.render()}"
         is ConeKotlinTypeProjectionIn -> "in ${type.render()}"
         is ConeKotlinTypeProjectionOut -> "out ${type.render()}"
         is ConeKotlinType -> render()