[FIR] Make check for dangling modifier lists use stubs

Seventh step for ^KT-52615

Merge-request: KT-MR-8651
Merged-by: Egor Kulikov <Egor.Kulikov@jetbrains.com>

compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt

@@ -1066,7 +1066,7 @@ open class RawFirBuilder(
                     }
                 }
 
-                for (danglingModifierList in PsiTreeUtil.getChildrenOfTypeAsList(file, KtModifierList::class.java)) {
+                for (danglingModifierList in file.danglingModifierLists) {
                     declarations += buildErrorTopLevelDeclarationForDanglingModifierList(danglingModifierList)
                 }
             }
@@ -1284,7 +1284,7 @@ open class RawFirBuilder(
                                 )
                             )
                         }
-                        for (danglingModifier in PsiTreeUtil.getChildrenOfTypeAsList(classOrObject.body, KtModifierList::class.java)) {
+                        for (danglingModifier in classOrObject.body?.danglingModifierLists ?: emptyList()) {
                             addDeclaration(
                                 buildErrorTopLevelDeclarationForDanglingModifierList(danglingModifier).apply {
                                     containingClassAttr = currentDispatchReceiverType()?.lookupTag
@@ -1383,7 +1383,7 @@ open class RawFirBuilder(
                             )
                         }
 
-                        for (danglingModifier in PsiTreeUtil.getChildrenOfTypeAsList(objectDeclaration.body, KtModifierList::class.java)) {
+                        for (danglingModifier in objectDeclaration.body?.danglingModifierLists ?: emptyList()) {
                             declarations += buildErrorTopLevelDeclarationForDanglingModifierList(danglingModifier).apply {
                                 containingClassAttr = currentDispatchReceiverType()?.lookupTag
                             }

compiler/psi/src/org/jetbrains/kotlin/psi/KtClassBody.kt

@@ -69,5 +69,11 @@ class KtClassBody : KtElementImplStub<KotlinPlaceHolderStub<KtClassBody>>, KtDec
      * @return annotations that do not belong to any declaration due to incomplete code or syntax errors
      */
     val danglingAnnotations: List<KtAnnotationEntry>
-        get() = getStubOrPsiChildrenAsList(MODIFIER_LIST).flatMap { it.annotationEntries }
+        get() = danglingModifierLists.flatMap { it.annotationEntries }
+
+    /**
+     * @return modifier lists that do not belong to any declaration due to incomplete code or syntax errors
+     */
+    val danglingModifierLists: List<KtModifierList>
+        get() = getStubOrPsiChildrenAsList(MODIFIER_LIST)
 }

compiler/psi/src/org/jetbrains/kotlin/psi/KtFile.kt

@@ -128,18 +128,23 @@ open class KtFile(viewProvider: FileViewProvider, val isCompiled: Boolean) :
         get() = script != null
 
     /**
-     * @return annotations that do not belong to any declaration due to incomplete code or syntax errors
+     * @return modifier lists that do not belong to any declaration due to incomplete code or syntax errors
      */
-    val danglingAnnotations: List<KtAnnotationEntry>
+    val danglingModifierLists: Array<out KtModifierList>
         get() {
             val stub = stub
-            val danglingModifierLists = stub?.getChildrenByType(
+            return stub?.getChildrenByType(
                 KtStubElementTypes.MODIFIER_LIST,
                 KtStubElementTypes.MODIFIER_LIST.arrayFactory
             ) ?: findChildrenByClass(KtModifierList::class.java)
-            return danglingModifierLists.flatMap { obj: KtModifierList -> obj.annotationEntries }
         }
 
+    /**
+     * @return annotations that do not belong to any declaration due to incomplete code or syntax errors
+     */
+    val danglingAnnotations: List<KtAnnotationEntry>
+        get() = danglingModifierLists.flatMap { obj: KtModifierList -> obj.annotationEntries }
+
     override fun getFileType(): FileType = KotlinFileType.INSTANCE
 
     override fun toString(): String = "KtFile: $name"