Add Kotlin package FQ name to kotlin.Metadata

It might differ from the JVM package FQ name if the JvmPackageName
annotation is used. This will be useful for faster indexing in the IDE
and for reflection

compiler/backend/src/org/jetbrains/kotlin/codegen/PackagePartCodegen.java

@@ -31,8 +31,10 @@ import org.jetbrains.kotlin.descriptors.annotations.Annotated;
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor;
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationsImpl;
 import org.jetbrains.kotlin.load.kotlin.header.KotlinClassHeader;
+import org.jetbrains.kotlin.name.FqName;
 import org.jetbrains.kotlin.psi.*;
 import org.jetbrains.kotlin.resolve.BindingContext;
+import org.jetbrains.kotlin.resolve.jvm.JvmClassName;
 import org.jetbrains.kotlin.serialization.DescriptorSerializer;
 import org.jetbrains.kotlin.serialization.ProtoBuf;
 import org.jetbrains.org.objectweb.asm.Type;
@@ -41,6 +43,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 import static org.jetbrains.kotlin.codegen.AsmUtil.writeAnnotationData;
+import static org.jetbrains.kotlin.load.java.JvmAnnotationNames.METADATA_PACKAGE_NAME_FIELD_NAME;
 import static org.jetbrains.org.objectweb.asm.Opcodes.*;
 
 public class PackagePartCodegen extends MemberCodegen<KtFile> {
@@ -104,6 +107,12 @@ public class PackagePartCodegen extends MemberCodegen<KtFile> {
 
         WriteAnnotationUtilKt.writeKotlinMetadata(v, state, KotlinClassHeader.Kind.FILE_FACADE, 0, av -> {
             writeAnnotationData(av, serializedPart.getFirst(), serializedPart.getSecond());
+
+            FqName kotlinPackageFqName = element.getPackageFqName();
+            if (!kotlinPackageFqName.equals(JvmClassName.byInternalName(packagePartType.getInternalName()).getPackageFqName())) {
+                av.visit(METADATA_PACKAGE_NAME_FIELD_NAME, kotlinPackageFqName.asString());
+            }
+
             return Unit.INSTANCE;
         });
     }

compiler/testData/codegen/box/jvmPackageName/metadataField.kt

@@ -0,0 +1,28 @@
+// TARGET_BACKEND: JVM
+// WITH_RUNTIME
+// LANGUAGE_VERSION: 1.2
+
+// FILE: foo.kt
+
+@file:Suppress("INVISIBLE_REFERENCE", "INVISIBLE_MEMBER")
+@file:JvmPackageName("baz.foo.quux.bar")
+package foo.bar
+
+fun f() {}
+
+// FILE: bar.kt
+
+@file:Suppress("INVISIBLE_REFERENCE", "INVISIBLE_MEMBER")
+
+fun getPackageName(classFqName: String): String =
+        Class.forName(classFqName).getAnnotation(Metadata::class.java).pn
+
+fun box(): String {
+    val bar = getPackageName("BarKt")
+    if (bar != "") return "Fail 1: $bar"
+
+    val foo = getPackageName("baz.foo.quux.bar.FooKt")
+    if (foo != "foo.bar") return "Fail 2: $foo"
+
+    return "OK"
+}

compiler/tests-ir-jvm/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -10568,6 +10568,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/jvmPackageName"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM, true);
         }
 
+        @TestMetadata("metadataField.kt")
+        public void testMetadataField() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/jvmPackageName/metadataField.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("rootPackage.kt")
         public void testRootPackage() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/jvmPackageName/rootPackage.kt");

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -10568,6 +10568,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/jvmPackageName"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM, true);
         }
 
+        @TestMetadata("metadataField.kt")
+        public void testMetadataField() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/jvmPackageName/metadataField.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("rootPackage.kt")
         public void testRootPackage() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/jvmPackageName/rootPackage.kt");

compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -10568,6 +10568,12 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/jvmPackageName"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM, true);
         }
 
+        @TestMetadata("metadataField.kt")
+        public void testMetadataField() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/jvmPackageName/metadataField.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("rootPackage.kt")
         public void testRootPackage() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/jvmPackageName/rootPackage.kt");