[FIR] Properly use FirContainingNamesAwareScope in all places

Split some delegating scopes to basic and name aware implementations

Also get rid of getContainingCallableNamesIfPresent and
  getContainingClassifierNamesIfPresent functions because they are not
  needed anymore

compiler/fir/tree/src/org/jetbrains/kotlin/fir/scopes/FirCompositeScope.kt

@@ -12,8 +12,7 @@ import org.jetbrains.kotlin.fir.symbols.impl.FirNamedFunctionSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirVariableSymbol
 import org.jetbrains.kotlin.name.Name
 
-class FirCompositeScope(val scopes: Iterable<FirScope>) : FirContainingNamesAwareScope() {
-
+class FirCompositeScope(val scopes: Iterable<FirScope>) : FirScope() {
     override fun processClassifiersByNameWithSubstitution(
         name: Name,
         processor: (FirClassifierSymbol<*>, ConeSubstitutor) -> Unit
@@ -64,15 +63,41 @@ class FirCompositeScope(val scopes: Iterable<FirScope>) : FirContainingNamesAwar
         processComposite(FirScope::processDeclaredConstructors, processor)
     }
 
-    override fun getCallableNames(): Set<Name> {
-        return scopes.flatMapTo(hashSetOf()) { it.getContainingCallableNamesIfPresent() }
-    }
-
-    override fun getClassifierNames(): Set<Name> {
-        return scopes.flatMapTo(hashSetOf()) { it.getContainingClassifierNamesIfPresent() }
-    }
-
     override val scopeOwnerLookupNames: List<String> by lazy(LazyThreadSafetyMode.PUBLICATION) {
         scopes.flatMap { it.scopeOwnerLookupNames }
     }
 }
+
+class FirNameAwareCompositeScope(val scopes: Iterable<FirContainingNamesAwareScope>) : FirContainingNamesAwareScope() {
+    private val delegate = FirCompositeScope(scopes)
+
+    override fun processClassifiersByNameWithSubstitution(
+        name: Name,
+        processor: (FirClassifierSymbol<*>, ConeSubstitutor) -> Unit
+    ) {
+        delegate.processClassifiersByNameWithSubstitution(name, processor)
+    }
+
+    override fun processFunctionsByName(name: Name, processor: (FirNamedFunctionSymbol) -> Unit) {
+        delegate.processFunctionsByName(name, processor)
+    }
+
+    override fun processPropertiesByName(name: Name, processor: (FirVariableSymbol<*>) -> Unit) {
+        delegate.processPropertiesByName(name, processor)
+    }
+
+    override fun processDeclaredConstructors(processor: (FirConstructorSymbol) -> Unit) {
+        delegate.processDeclaredConstructors(processor)
+    }
+
+    override val scopeOwnerLookupNames: List<String>
+        get() = delegate.scopeOwnerLookupNames
+
+    override fun getCallableNames(): Set<Name> {
+        return scopes.flatMapTo(hashSetOf()) { it.getCallableNames() }
+    }
+
+    override fun getClassifierNames(): Set<Name> {
+        return scopes.flatMapTo(hashSetOf()) { it.getClassifierNames() }
+    }
+}

compiler/fir/tree/src/org/jetbrains/kotlin/fir/scopes/FirContainingNamesAwareScope.kt

@@ -15,12 +15,6 @@ abstract class FirContainingNamesAwareScope : FirScope() {
     abstract fun getClassifierNames(): Set<Name>
 }
 
-fun FirScope.getContainingCallableNamesIfPresent(): Set<Name> =
-    if (this is FirContainingNamesAwareScope) getCallableNames() else emptySet()
-
-fun FirScope.getContainingClassifierNamesIfPresent(): Set<Name> =
-    if (this is FirContainingNamesAwareScope) getClassifierNames() else emptySet()
-
 fun FirContainingNamesAwareScope.processAllFunctions(processor: (FirNamedFunctionSymbol) -> Unit) {
     for (name in getCallableNames()) {
         processFunctionsByName(name, processor)

compiler/fir/tree/src/org/jetbrains/kotlin/fir/scopes/FirScopeProvider.kt

@@ -20,25 +20,25 @@ abstract class FirScopeProvider {
         klass: FirClass,
         useSiteSession: FirSession,
         scopeSession: ScopeSession
-    ): FirScope?
+    ): FirContainingNamesAwareScope?
 
     abstract fun getNestedClassifierScope(
         klass: FirClass,
         useSiteSession: FirSession,
         scopeSession: ScopeSession
-    ): FirScope?
+    ): FirContainingNamesAwareScope?
 
     fun getStaticScope(
         klass: FirClass,
         useSiteSession: FirSession,
         scopeSession: ScopeSession
-    ): FirScope? {
+    ): FirContainingNamesAwareScope? {
         val nestedClassifierScope = getNestedClassifierScope(klass, useSiteSession, scopeSession)
         val callableScope = getStaticMemberScopeForCallables(klass, useSiteSession, scopeSession)
 
         return when {
             nestedClassifierScope != null && callableScope != null ->
-                FirCompositeScope(listOf(nestedClassifierScope, callableScope))
+                FirNameAwareCompositeScope(listOf(nestedClassifierScope, callableScope))
             else -> nestedClassifierScope ?: callableScope
         }
     }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/scopes/FirUnstableSmartcastTypeScope.kt

@@ -102,11 +102,11 @@ class FirUnstableSmartcastTypeScope(
     }
 
     override fun getCallableNames(): Set<Name> {
-        return scopes.flatMapTo(hashSetOf()) { it.getContainingCallableNamesIfPresent() }
+        return scopes.flatMapTo(hashSetOf()) { it.getCallableNames() }
     }
 
     override fun getClassifierNames(): Set<Name> {
-        return scopes.flatMapTo(hashSetOf()) { it.getContainingClassifierNamesIfPresent() }
+        return scopes.flatMapTo(hashSetOf()) { it.getClassifierNames() }
     }
 
     override val scopeOwnerLookupNames: List<String> by lazy(LazyThreadSafetyMode.PUBLICATION) {