JVM_IR KT-43519 no delegates for external funs in multifile facades

Also add ABI tests for @JvmStatic/JvmOverloads + 'external'.

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/GenerateMultifileFacades.kt

@@ -145,6 +145,9 @@ private fun generateMultifileFacades(
             for (member in partClass.declarations) {
                 if (member !is IrSimpleFunction) continue
 
+                // KT-43519 Don't generate delegates for external methods
+                if (member.isExternal) continue
+
                 val correspondingProperty = member.correspondingPropertySymbol?.owner
                 if (member.hasAnnotation(INLINE_ONLY_ANNOTATION_FQ_NAME) ||
                     correspondingProperty?.hasAnnotation(INLINE_ONLY_ANNOTATION_FQ_NAME) == true

compiler/testData/codegen/bytecodeListing/jvmOverloadsExternal.kt

@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+
+@JvmOverloads
+external fun foo(x: Int = 42)

compiler/testData/codegen/bytecodeListing/jvmOverloadsExternal.txt

@@ -0,0 +1,7 @@
+@kotlin.Metadata
+public final class JvmOverloadsExternalKt {
+    // source: 'jvmOverloadsExternal.kt'
+    public synthetic static method foo$default(p0: int, p1: int, p2: java.lang.Object): void
+    public final static @kotlin.jvm.JvmOverloads method foo(): void
+    public native final static @kotlin.jvm.JvmOverloads method foo(p0: int): void
+}

compiler/testData/codegen/bytecodeListing/jvmStaticExternal.kt

@@ -0,0 +1,14 @@
+// WITH_RUNTIME
+// JVM_TARGET: 1.8
+
+object TestObject {
+    @JvmStatic
+    external fun foo()
+}
+
+class TestClassCompanion {
+    companion object {
+        @JvmStatic
+        external fun foo()
+    }
+}

compiler/testData/codegen/bytecodeListing/jvmStaticExternal.txt

@@ -0,0 +1,27 @@
+@kotlin.Metadata
+public final class TestClassCompanion$Companion {
+    // source: 'jvmStaticExternal.kt'
+    private method <init>(): void
+    public synthetic method <init>(p0: kotlin.jvm.internal.DefaultConstructorMarker): void
+    public final @kotlin.jvm.JvmStatic method foo(): void
+    public final inner class TestClassCompanion$Companion
+}
+
+@kotlin.Metadata
+public final class TestClassCompanion {
+    // source: 'jvmStaticExternal.kt'
+    public final static @org.jetbrains.annotations.NotNull field Companion: TestClassCompanion$Companion
+    static method <clinit>(): void
+    public method <init>(): void
+    public native final static @kotlin.jvm.JvmStatic method foo(): void
+    public final inner class TestClassCompanion$Companion
+}
+
+@kotlin.Metadata
+public final class TestObject {
+    // source: 'jvmStaticExternal.kt'
+    public final static @org.jetbrains.annotations.NotNull field INSTANCE: TestObject
+    static method <clinit>(): void
+    private method <init>(): void
+    public native final static @kotlin.jvm.JvmStatic method foo(): void
+}

compiler/testData/codegen/bytecodeListing/kt43519.kt

@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+@file:JvmMultifileClass()
+@file:JvmName("a")
+
+external fun externalFun(): Long

compiler/testData/codegen/bytecodeListing/kt43519.txt

@@ -0,0 +1,10 @@
+@kotlin.Metadata
+public final class a {
+    // source: 'kt43519.kt'
+}
+
+@kotlin.Metadata
+synthetic final class a__Kt43519Kt {
+    // source: 'kt43519.kt'
+    public native final static method externalFun(): long
+}

compiler/tests-gen/org/jetbrains/kotlin/codegen/BytecodeListingTestGenerated.java

@@ -99,6 +99,16 @@ public class BytecodeListingTestGenerated extends AbstractBytecodeListingTest {
         runTest("compiler/testData/codegen/bytecodeListing/jvmOverloadsAndParametersAnnotations.kt");
     }
 
+    @TestMetadata("jvmOverloadsExternal.kt")
+    public void testJvmOverloadsExternal() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeListing/jvmOverloadsExternal.kt");
+    }
+
+    @TestMetadata("jvmStaticExternal.kt")
+    public void testJvmStaticExternal() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeListing/jvmStaticExternal.kt");
+    }
+
     @TestMetadata("jvmStaticWithDefaultParameters.kt")
     public void testJvmStaticWithDefaultParameters() throws Exception {
         runTest("compiler/testData/codegen/bytecodeListing/jvmStaticWithDefaultParameters.kt");
@@ -124,6 +134,11 @@ public class BytecodeListingTestGenerated extends AbstractBytecodeListingTest {
         runTest("compiler/testData/codegen/bytecodeListing/kt43440.kt");
     }
 
+    @TestMetadata("kt43519.kt")
+    public void testKt43519() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeListing/kt43519.kt");
+    }
+
     @TestMetadata("localFunctionInInitBlock.kt")
     public void testLocalFunctionInInitBlock() throws Exception {
         runTest("compiler/testData/codegen/bytecodeListing/localFunctionInInitBlock.kt");

compiler/tests-gen/org/jetbrains/kotlin/codegen/ir/IrBytecodeListingTestGenerated.java

@@ -99,6 +99,16 @@ public class IrBytecodeListingTestGenerated extends AbstractIrBytecodeListingTes
         runTest("compiler/testData/codegen/bytecodeListing/jvmOverloadsAndParametersAnnotations.kt");
     }
 
+    @TestMetadata("jvmOverloadsExternal.kt")
+    public void testJvmOverloadsExternal() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeListing/jvmOverloadsExternal.kt");
+    }
+
+    @TestMetadata("jvmStaticExternal.kt")
+    public void testJvmStaticExternal() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeListing/jvmStaticExternal.kt");
+    }
+
     @TestMetadata("jvmStaticWithDefaultParameters.kt")
     public void testJvmStaticWithDefaultParameters() throws Exception {
         runTest("compiler/testData/codegen/bytecodeListing/jvmStaticWithDefaultParameters.kt");
@@ -124,6 +134,11 @@ public class IrBytecodeListingTestGenerated extends AbstractIrBytecodeListingTes
         runTest("compiler/testData/codegen/bytecodeListing/kt43440.kt");
     }
 
+    @TestMetadata("kt43519.kt")
+    public void testKt43519() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeListing/kt43519.kt");
+    }
+
     @TestMetadata("localFunctionInInitBlock.kt")
     public void testLocalFunctionInInitBlock() throws Exception {
         runTest("compiler/testData/codegen/bytecodeListing/localFunctionInInitBlock.kt");