FirProperty: return back 'isReferredViaField' attribute

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrDeclarationStorage.kt

@@ -679,7 +679,7 @@ class Fir2IrDeclarationStorage(
                         if (initializer != null ||
                             getter is FirDefaultPropertyGetter ||
                             property.isVar && setter is FirDefaultPropertySetter ||
-                            property.backingFieldSymbol.isReferenced
+                            property.isReferredViaField == true
                         ) {
                             backingField = createBackingField(
                                 property, IrDeclarationOrigin.PROPERTY_BACKING_FIELD, descriptor,

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/FirCallResolver.kt

@@ -6,10 +6,7 @@
 package org.jetbrains.kotlin.fir
 
 import org.jetbrains.kotlin.descriptors.ClassKind
-import org.jetbrains.kotlin.fir.declarations.FirMemberDeclaration
-import org.jetbrains.kotlin.fir.declarations.FirRegularClass
-import org.jetbrains.kotlin.fir.declarations.FirTypeParameter
-import org.jetbrains.kotlin.fir.declarations.isInner
+import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.diagnostics.ConeDiagnostic
 import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.expressions.builder.buildExpressionStub
@@ -515,7 +512,7 @@ class FirCallResolver(
                 val candidate = candidates.single()
                 val coneSymbol = candidate.symbol
                 if (coneSymbol is FirBackingFieldSymbol) {
-                    coneSymbol.isReferenced = true
+                    coneSymbol.fir.isReferredViaField = true
                     return buildBackingFieldReference {
                         this.source = source
                         resolvedSymbol = coneSymbol

compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/FirDeclarationUtil.kt

@@ -116,6 +116,8 @@ fun FirRegularClass.addDeclaration(declaration: FirDeclaration) {
 
 private object IsFromVarargKey : FirDeclarationDataKey()
 var FirProperty.isFromVararg: Boolean? by FirDeclarationDataRegistry.data(IsFromVarargKey)
+private object IsReferredViaField : FirDeclarationDataKey()
+var FirProperty.isReferredViaField: Boolean? by FirDeclarationDataRegistry.data(IsReferredViaField)
 
 inline val FirProperty.hasJvmFieldAnnotation: Boolean
     get() = annotations.any {

compiler/fir/tree/src/org/jetbrains/kotlin/fir/symbols/impl/FirVariableSymbol.kt

@@ -32,10 +32,7 @@ open class FirPropertySymbol(
     constructor(name: Name) : this(CallableId(name))
 }
 
-class FirBackingFieldSymbol(
-    callableId: CallableId,
-    var isReferenced: Boolean = false
-) : FirVariableSymbol<FirProperty>(callableId)
+class FirBackingFieldSymbol(callableId: CallableId) : FirVariableSymbol<FirProperty>(callableId)
 
 class FirDelegateFieldSymbol<D : FirVariable<D>>(callableId: CallableId) : FirVariableSymbol<D>(callableId) {
     val delegate: FirExpression