[LL FIR] KTIJ-25536 Add callable package names workaround for LLFirProvider$SymbolProvider

- Sadly, the only way for now is to disable computation of the callable
  package names, which will negatively affect performance.

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

@@ -83,7 +83,10 @@ internal class LLFirProviderHelper(
     val symbolNameCache = FirCompositeCachedSymbolNamesProvider.create(
         firSession,
         listOfNotNull(
-            LLFirKotlinSymbolNamesProvider(declarationProvider),
+            object : LLFirKotlinSymbolNamesProvider(declarationProvider) {
+                // This is a temporary workaround for KTIJ-25536.
+                override fun getPackageNamesWithTopLevelCallables(): Set<String>? = null
+            },
             extensionTool?.symbolNamesProvider,
         )
     )

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

@@ -16,7 +16,7 @@ import org.jetbrains.kotlin.name.Name
 /**
  * A [FirSymbolNamesProvider] that fetches top-level names from a Kotlin [declarationProvider].
  */
-internal class LLFirKotlinSymbolNamesProvider(
+internal open class LLFirKotlinSymbolNamesProvider(
     private val declarationProvider: KotlinDeclarationProvider,
 ) : FirSymbolNamesProvider() {
     override fun getTopLevelClassifierNamesInPackage(packageFqName: FqName): Set<String> =
@@ -24,7 +24,7 @@ internal class LLFirKotlinSymbolNamesProvider(
             .getTopLevelKotlinClassLikeDeclarationNamesInPackage(packageFqName)
             .mapTo(mutableSetOf()) { it.asString() }
 
-    override fun getPackageNamesWithTopLevelCallables(): Set<String> =
+    override fun getPackageNamesWithTopLevelCallables(): Set<String>? =
         declarationProvider.computePackageSetWithTopLevelCallableDeclarations()
 
     override fun getTopLevelCallableNamesInPackage(packageFqName: FqName): Set<Name> =