[FIR] FirSyntheticProperty: make constructor internal

Also, backingField can be moved into the body

^KT-61990

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/scopes/JavaAnnotationSyntheticPropertiesScope.kt

@@ -9,18 +9,18 @@ import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.copy
 import org.jetbrains.kotlin.fir.declarations.FirSimpleFunction
-import org.jetbrains.kotlin.fir.declarations.synthetic.FirSyntheticProperty
-import org.jetbrains.kotlin.fir.declarations.synthetic.FirSyntheticPropertyAccessor
+import org.jetbrains.kotlin.fir.declarations.UnresolvedDeprecationProvider
+import org.jetbrains.kotlin.fir.declarations.getDeprecationsProviderFromAccessors
+import org.jetbrains.kotlin.fir.declarations.synthetic.buildSyntheticProperty
 import org.jetbrains.kotlin.fir.java.symbols.FirJavaOverriddenSyntheticPropertySymbol
 import org.jetbrains.kotlin.fir.nullableModuleData
+import org.jetbrains.kotlin.fir.scopes.FirDelegatingTypeScope
 import org.jetbrains.kotlin.fir.scopes.FirTypeScope
 import org.jetbrains.kotlin.fir.scopes.ProcessorAction
 import org.jetbrains.kotlin.fir.symbols.impl.*
 import org.jetbrains.kotlin.name.CallableId
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.Name
-import org.jetbrains.kotlin.fir.declarations.resolvePhase
-import org.jetbrains.kotlin.fir.scopes.FirDelegatingTypeScope
 
 class JavaAnnotationSyntheticPropertiesScope(
     private val session: FirSession,
@@ -43,18 +43,17 @@ class JavaAnnotationSyntheticPropertiesScope(
             val symbol = syntheticPropertiesCache.getOrPut(functionSymbol) {
                 val callableId = CallableId(classId, name)
                 FirJavaOverriddenSyntheticPropertySymbol(callableId, callableId).also {
-                    val accessor = FirSyntheticPropertyAccessor(function, isGetter = true, it)
-                    FirSyntheticProperty(
-                        session.nullableModuleData ?: function.moduleData,
-                        name,
-                        isVar = false,
-                        it,
-                        function.status.copy(modality = Modality.FINAL),
-                        function.resolvePhase,
-                        accessor
-                    )
+                    buildSyntheticProperty {
+                        moduleData = session.nullableModuleData ?: function.moduleData
+                        this.name = name
+                        symbol = it
+                        status = function.status.copy(modality = Modality.FINAL)
+                        delegateGetter = function
+                        deprecationsProvider = UnresolvedDeprecationProvider
+                    }
                 }
             }
+
             processor(symbol)
         }
     }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/synthetic/FirSyntheticProperty.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.fir.declarations.synthetic
 
 import org.jetbrains.kotlin.KtSourceElement
+import org.jetbrains.kotlin.fir.FirImplementationDetail
 import org.jetbrains.kotlin.fir.FirModuleData
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.expressions.FirAnnotation
@@ -20,7 +21,7 @@ import org.jetbrains.kotlin.fir.visitors.FirVisitor
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.serialization.deserialization.descriptors.DeserializedContainerSource
 
-class FirSyntheticProperty(
+class FirSyntheticProperty @FirImplementationDetail internal constructor(
     override val moduleData: FirModuleData,
     override val name: Name,
     override val isVar: Boolean,
@@ -29,7 +30,6 @@ class FirSyntheticProperty(
     resolvePhase: FirResolvePhase,
     override val getter: FirSyntheticPropertyAccessor,
     override val setter: FirSyntheticPropertyAccessor? = null,
-    override val backingField: FirBackingField? = null,
     override val deprecationsProvider: DeprecationsProvider = UnresolvedDeprecationProvider
 ) : FirProperty() {
     init {
@@ -41,6 +41,8 @@ class FirSyntheticProperty(
         this.resolveState = resolvePhase.asResolveState()
     }
 
+    override val backingField: FirBackingField? get() = null
+
     override val returnTypeRef: FirTypeRef
         get() = getter.returnTypeRef
 

compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/synthetic/FirSyntheticPropertyAccessor.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.fir.declarations.synthetic
 
 import org.jetbrains.kotlin.KtSourceElement
+import org.jetbrains.kotlin.fir.FirImplementationDetail
 import org.jetbrains.kotlin.fir.FirModuleData
 import org.jetbrains.kotlin.fir.contracts.FirContractDescription
 import org.jetbrains.kotlin.fir.contracts.impl.FirEmptyContractDescription
@@ -22,7 +23,7 @@ import org.jetbrains.kotlin.fir.visitors.FirTransformer
 import org.jetbrains.kotlin.fir.visitors.FirVisitor
 import org.jetbrains.kotlin.serialization.deserialization.descriptors.DeserializedContainerSource
 
-class FirSyntheticPropertyAccessor(
+class FirSyntheticPropertyAccessor @FirImplementationDetail internal constructor(
     val delegate: FirSimpleFunction,
     override val isGetter: Boolean,
     override val propertySymbol: FirPropertySymbol,

compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/synthetic/FirSyntheticPropertyBuilder.kt

@@ -5,6 +5,7 @@
 
 package org.jetbrains.kotlin.fir.declarations.synthetic
 
+import org.jetbrains.kotlin.fir.FirImplementationDetail
 import org.jetbrains.kotlin.fir.FirModuleData
 import org.jetbrains.kotlin.fir.declarations.DeprecationsProvider
 import org.jetbrains.kotlin.fir.declarations.FirDeclarationStatus
@@ -24,6 +25,7 @@ class FirSyntheticPropertyBuilder {
     var delegateSetter: FirSimpleFunction? = null
 
 
+    @OptIn(FirImplementationDetail::class)
     fun build(): FirSyntheticProperty = FirSyntheticProperty(
         moduleData, name, isVar = delegateSetter != null, symbol = symbol,
         status = status ?: delegateGetter.status,