[FIR] Make anonymous initializer lazy in RawFirBuilder

Fourth step for KT-52615

Merge-request: KT-MR-7798
Merged-by: Egor Kulikov <Egor.Kulikov@jetbrains.com>

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/FirAnonymousInitializer.kt

@@ -40,5 +40,7 @@ abstract class FirAnonymousInitializer : FirDeclaration(), FirControlFlowGraphOw
 
     abstract override fun replaceControlFlowGraphReference(newControlFlowGraphReference: FirControlFlowGraphReference?)
 
+    abstract fun replaceBody(newBody: FirBlock?)
+
     abstract override fun <D> transformAnnotations(transformer: FirTransformer<D>, data: D): FirAnonymousInitializer
 }

compiler/fir/tree/gen/org/jetbrains/kotlin/fir/declarations/impl/FirAnonymousInitializerImpl.kt

@@ -63,4 +63,8 @@ internal class FirAnonymousInitializerImpl(
     override fun replaceControlFlowGraphReference(newControlFlowGraphReference: FirControlFlowGraphReference?) {
         controlFlowGraphReference = newControlFlowGraphReference
     }
+
+    override fun replaceBody(newBody: FirBlock?) {
+        body = newBody
+    }
 }

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

@@ -437,7 +437,7 @@ object NodeConfigurator : AbstractFieldConfigurator<FirTreeBuilder>(FirTreeBuild
         }
 
         anonymousInitializer.configure {
-            +body(nullable = true)
+            +body(nullable = true, withReplace = true)
             +symbol("FirAnonymousInitializerSymbol")
         }