[Wasm] Add external inheritance checker.

Prohibit non-external types to extend external types.
This type of inheritance is not supported in Wasm backend.

wasm/wasm.frontend/src/org/jetbrains/kotlin/wasm/resolve/diagnostics/DefaultErrorMessagesWasm.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.wasm.resolve.diagnostics
+
+import org.jetbrains.kotlin.diagnostics.rendering.DefaultErrorMessages
+import org.jetbrains.kotlin.diagnostics.rendering.DiagnosticFactoryToRendererMap
+import org.jetbrains.kotlin.diagnostics.rendering.Renderers
+
+private val DIAGNOSTIC_FACTORY_TO_RENDERER by lazy {
+    DiagnosticFactoryToRendererMap("Wasm").apply {
+        put(
+            ErrorsWasm.NON_EXTERNAL_TYPE_EXTENDS_EXTERNAL_TYPE,
+            "Non-external type extends external type {0}",
+            Renderers.RENDER_TYPE
+        )
+    }
+}
+
+class DefaultErrorMessagesWasm : DefaultErrorMessages.Extension {
+    override fun getMap(): DiagnosticFactoryToRendererMap = DIAGNOSTIC_FACTORY_TO_RENDERER
+}

wasm/wasm.frontend/src/org/jetbrains/kotlin/wasm/resolve/diagnostics/ErrorsWasm.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.wasm.resolve.diagnostics;
+
+import com.intellij.psi.PsiElement;
+import org.jetbrains.kotlin.diagnostics.DiagnosticFactory0;
+import org.jetbrains.kotlin.diagnostics.DiagnosticFactory1;
+import org.jetbrains.kotlin.diagnostics.Errors;
+import org.jetbrains.kotlin.diagnostics.PositioningStrategies;
+import org.jetbrains.kotlin.psi.KtElement;
+import org.jetbrains.kotlin.types.KotlinType;
+
+import static org.jetbrains.kotlin.diagnostics.Severity.ERROR;
+
+public interface ErrorsWasm {
+    DiagnosticFactory1<KtElement, KotlinType> NON_EXTERNAL_TYPE_EXTENDS_EXTERNAL_TYPE =
+            DiagnosticFactory1.create(ERROR, PositioningStrategies.DECLARATION_SIGNATURE_OR_DEFAULT);
+
+    @SuppressWarnings("UnusedDeclaration")
+    Object _initializer = new Object() {
+        {
+            Errors.Initializer.initializeFactoryNames(ErrorsWasm.class);
+        }
+    };
+}

wasm/wasm.frontend/src/org/jetbrains/kotlin/wasm/resolve/diagnostics/WasmExternalInheritanceChecker.kt

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.wasm.resolve.diagnostics
+
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
+import org.jetbrains.kotlin.psi.KtClassOrObject
+import org.jetbrains.kotlin.psi.KtDeclaration
+import org.jetbrains.kotlin.resolve.checkers.DeclarationChecker
+import org.jetbrains.kotlin.resolve.checkers.DeclarationCheckerContext
+import org.jetbrains.kotlin.resolve.descriptorUtil.getSuperClassNotAny
+import org.jetbrains.kotlin.resolve.descriptorUtil.getSuperInterfaces
+import org.jetbrains.kotlin.resolve.descriptorUtil.isEffectivelyExternal
+
+// TODO: Implement in K2
+object WasmExternalInheritanceChecker : DeclarationChecker {
+    override fun check(declaration: KtDeclaration, descriptor: DeclarationDescriptor, context: DeclarationCheckerContext) {
+        if (descriptor is ClassDescriptor && !descriptor.isEffectivelyExternal()) {
+            val superClasses = listOfNotNull(descriptor.getSuperClassNotAny()) + descriptor.getSuperInterfaces()
+            for (superClass in superClasses) {
+                if (superClass.isEffectivelyExternal()) {
+                    context.trace.report(
+                        ErrorsWasm.NON_EXTERNAL_TYPE_EXTENDS_EXTERNAL_TYPE.on(
+                            declaration as KtClassOrObject,
+                            superClass.defaultType
+                        )
+                    )
+                }
+            }
+        }
+    }
+}