FIR: add smartcast stability to FIR

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/FieldSets.kt

@@ -83,4 +83,6 @@ object FieldSets {
     val modality = field(modalityType, nullable = true)
 
     val scopeProvider = field("scopeProvider", firScopeProviderType)
+
+    val smartcastStability = field(smartcastStabilityType)
 }

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/NodeConfigurator.kt

@@ -19,6 +19,7 @@ import org.jetbrains.kotlin.fir.tree.generator.FieldSets.name
 import org.jetbrains.kotlin.fir.tree.generator.FieldSets.receivers
 import org.jetbrains.kotlin.fir.tree.generator.FieldSets.returnTypeRef
 import org.jetbrains.kotlin.fir.tree.generator.FieldSets.scopeProvider
+import org.jetbrains.kotlin.fir.tree.generator.FieldSets.smartcastStability
 import org.jetbrains.kotlin.fir.tree.generator.FieldSets.status
 import org.jetbrains.kotlin.fir.tree.generator.FieldSets.superTypeRefs
 import org.jetbrains.kotlin.fir.tree.generator.FieldSets.symbol
@@ -462,6 +463,8 @@ object NodeConfigurator : AbstractFieldConfigurator<FirTreeBuilder>(FirTreeBuild
             +field("originalExpression", qualifiedAccessExpression)
             +field("typesFromSmartCast", "Collection<ConeKotlinType>", null, customType = coneKotlinTypeType)
             +field("originalType", typeRef)
+            +field("smartcastType", typeRef)
+            +smartcastStability
         }
 
         expressionWithSmartcastToNull.configure {

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/Types.kt

@@ -17,6 +17,7 @@ import org.jetbrains.kotlin.fir.types.ConeKotlinType
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.types.SmartcastStability
 import org.jetbrains.kotlin.types.Variance
 
 val sourceElementType = type("fir", "FirSourceElement")
@@ -31,6 +32,7 @@ val nameType = type(Name::class)
 val visibilityType = type(Visibility::class)
 val effectiveVisibilityType = type("descriptors", "EffectiveVisibility")
 val modalityType = type(Modality::class)
+val smartcastStabilityType = type(SmartcastStability::class)
 val fqNameType = type(FqName::class)
 val classIdType = type(ClassId::class)
 val annotationUseSiteTargetType = type(AnnotationUseSiteTarget::class)