[Low Level API FIR] fix invalid traverse of supertypes list

the supertypes list should not be traversed without proper locking,
otherwise some transformer may transform it concurrently

In case of looking for a declaration by class id it just should not be traversed

^KTIJ-21791

analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/providers/LLFirProviderHelper.kt

@@ -18,6 +18,7 @@ import org.jetbrains.kotlin.analysis.low.level.api.fir.file.builder.LLFirFileBui
 import org.jetbrains.kotlin.analysis.low.level.api.fir.file.builder.ModuleFileCache
 import org.jetbrains.kotlin.analysis.low.level.api.fir.util.FirElementFinder
 import org.jetbrains.kotlin.analysis.low.level.api.fir.util.executeOrReturnDefaultValueOnPCE
+import org.jetbrains.kotlin.fir.declarations.FirRegularClass
 import org.jetbrains.kotlin.name.CallableId
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.FqName
@@ -39,9 +40,11 @@ internal class LLFirProviderHelper(
                     ?: return@computeIfAbsent Optional.empty()
                 if (ktClass.getClassId() == null) return@computeIfAbsent Optional.empty()
                 val firFile = firFileBuilder.buildRawFirFileWithCaching(ktClass.containingKtFile)
-                val classifier = FirElementFinder.findElementIn<FirClassLikeDeclaration>(firFile) { classifier ->
+                val classifier = FirElementFinder.findElementIn<FirClassLikeDeclaration>(
-                    classifier.symbol.classId == classId
+                    firFile,
-                }
+                    canGoInside = { it is FirRegularClass },
+                    predicate = { it.symbol.classId == classId },
+                )
                     ?: error("Classifier $classId was found in file ${ktClass.containingKtFile.virtualFilePath} but was not found in FirFile")
                 Optional.of(classifier)
             }.getOrNull()

analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/util/FirNonLocalDeclarationSearcher.kt

@@ -9,7 +9,6 @@ import org.jetbrains.kotlin.fir.FirElement
 import org.jetbrains.kotlin.fir.declarations.FirFile
 import org.jetbrains.kotlin.fir.declarations.FirRegularClass
 import org.jetbrains.kotlin.fir.declarations.utils.classId
-import org.jetbrains.kotlin.fir.psi
 import org.jetbrains.kotlin.fir.render
 import org.jetbrains.kotlin.fir.visitors.FirVisitorVoid
 import org.jetbrains.kotlin.psi.KtElement
@@ -17,7 +16,7 @@ import org.jetbrains.kotlin.psi.KtElement
 object FirElementFinder {
     inline fun <reified E : FirElement> findElementIn(
         container: FirElement,
-        crossinline goInside: (E) -> Boolean = { true },
+        crossinline canGoInside: (E) -> Boolean = { true },
         crossinline predicate: (E) -> Boolean,
     ): E? {
         var result: E? = null
@@ -31,7 +30,7 @@ object FirElementFinder {
                     predicate(element) -> {
                         result = element
                     }
-                    goInside(element) -> {
+                    canGoInside(element) -> {
                         element.acceptChildren(this)
                     }
                 }
@@ -61,7 +60,4 @@ object FirElementFinder {
         })
         return result
     }
-
-    inline fun <reified E : FirElement> findElementByPsiIn(container: FirElement, ktElement: KtElement): E? =
-        findElementIn(container) { it.psi === ktElement }
 }

analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/util/declarationUtils.kt

@@ -15,7 +15,6 @@ import org.jetbrains.kotlin.fir.declarations.FirRegularClass
 import org.jetbrains.kotlin.fir.psi
 import org.jetbrains.kotlin.fir.realPsi
 import org.jetbrains.kotlin.fir.resolve.providers.FirProvider
-import org.jetbrains.kotlin.fir.resolve.providers.FirSymbolProvider
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.containingClassOrObject
 
@@ -63,7 +62,7 @@ private fun KtDeclaration.findSourceOfNonLocalFirDeclarationByTraversingWholeTre
 ): FirDeclaration? {
     val firFile = containerFirFile ?: firFileBuilder.buildRawFirFileWithCaching(containingKtFile)
     val originalDeclaration = originalDeclaration
-    return FirElementFinder.findElementIn(firFile, goInside = { it is FirRegularClass }) { firDeclaration ->
+    return FirElementFinder.findElementIn(firFile, canGoInside = { it is FirRegularClass }) { firDeclaration ->
         firDeclaration.psi == this || firDeclaration.psi == originalDeclaration
     }
 }