Refactor and rename CodegenUtil.getDeclarationsToGenerate

Move logic regarding expect classes to the only relevant call site at
PackageCodegenImpl, and return the list of members to remove code
duplication at remaining call sites

compiler/backend-common/src/org/jetbrains/kotlin/backend/common/CodegenUtil.kt

@@ -20,7 +20,6 @@ import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.bindingContextUtil.isUsedAsExpression
 import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
-import org.jetbrains.kotlin.resolve.checkers.ExpectedActualDeclarationChecker
 import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.utils.DFS
@@ -169,23 +168,19 @@ object CodegenUtil {
     }
 
     /**
-     * Returns declarations in the given [file] which should be generated by the back-end. This includes all declarations
-     * minus all expected declarations (except annotation classes annotated with @OptionalExpectation).
+     * Returns functions, properties and type aliases in the given [file] which should be generated by the back-end.
      */
     @JvmStatic
-    fun getDeclarationsToGenerate(file: KtFile, bindingContext: BindingContext): List<KtDeclaration> =
-        file.declarations.filter(fun(declaration: KtDeclaration): Boolean {
-            if (!declaration.hasExpectModifier()) return true
+    fun getMemberDeclarationsToGenerate(file: KtFile): List<KtDeclaration> =
+        file.declarations.filter { declaration ->
+            !declaration.hasExpectModifier() && (declaration is KtNamedFunction || declaration is KtProperty || declaration is KtTypeAlias)
+        }
 
-            if (declaration is KtClass) {
-                val descriptor = bindingContext.get(BindingContext.CLASS, declaration)
-                if (descriptor != null && ExpectedActualDeclarationChecker.shouldGenerateExpectClass(descriptor)) {
-                    return true
-                }
-            }
-
-            return false
-        })
+    @JvmStatic
+    fun getMemberDescriptorsToGenerate(file: KtFile, bindingContext: BindingContext): List<MemberDescriptor> =
+        getMemberDeclarationsToGenerate(file).mapNotNull { declaration ->
+            bindingContext.get(BindingContext.DECLARATION_TO_DESCRIPTOR, declaration) as MemberDescriptor?
+        }
 
     @JvmStatic
     fun findExpectedFunctionForActual(descriptor: FunctionDescriptor): FunctionDescriptor? {