Do not serialize constructors for anonymous objects

The only client of this data is reflection, and since anonymous objects
do not have constructors in the source code, they shouldn't in
reflection as well

 #KT-20442 Fixed

compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt

@@ -89,7 +89,7 @@ class DescriptorSerializer private constructor(
             }
         }
 
-        if (classDescriptor.kind != ClassKind.ENUM_ENTRY) {
+        if (!DescriptorUtils.isAnonymousObject(classDescriptor) && classDescriptor.kind != ClassKind.ENUM_ENTRY) {
             for (descriptor in classDescriptor.constructors) {
                 builder.addConstructor(constructorProto(descriptor))
             }

compiler/testData/codegen/box/reflection/constructors/classesWithoutConstructors.kt

@@ -18,6 +18,7 @@ fun box(): String {
     assertTrue(Interface::class.constructors.isEmpty())
     assertTrue(Obj::class.constructors.isEmpty())
     assertTrue(C.Companion::class.constructors.isEmpty())
+    assertTrue(object {}::class.constructors.isEmpty())
 
     return "OK"
 }

compiler/testData/codegen/box/reflection/constructors/primaryConstructor.kt

@@ -49,11 +49,13 @@ fun box(): String {
     val p4 = TwoSecondaries::class.primaryConstructor
     assertNull(p4)
 
-    assertNotNull(En::class.primaryConstructor) // TODO: maybe primaryConstructor should be null for enum classes
+    assertNotNull(En::class.primaryConstructor)
 
     assertNull(I::class.primaryConstructor)
     assertNull(O::class.primaryConstructor)
     assertNull(C.Companion::class.primaryConstructor)
 
+    assertNull(object {}::class.primaryConstructor)
+
     return "OK"
 }

compiler/testData/serialization/local/anonymousObject.txt

@@ -1,4 +1,3 @@
 local final class `AnonymousObjectKt$main$1` : java.lang.Runnable
 
-public constructor `AnonymousObjectKt$main$1`()
 public open override /*1*/ fun run(): kotlin.Unit

compiler/util/src/org/jetbrains/kotlin/utils/KotlinJavascriptMetadataUtils.kt

@@ -32,7 +32,7 @@ class JsMetadataVersion(vararg numbers: Int) : BinaryVersion(*numbers) {
 
     companion object {
         @JvmField
-        val INSTANCE = JsMetadataVersion(1, 2, 2)
+        val INSTANCE = JsMetadataVersion(1, 2, 3)
 
         @JvmField
         val INVALID_VERSION = JsMetadataVersion()

core/metadata.jvm/src/org/jetbrains/kotlin/metadata/jvm/deserialization/JvmMetadataVersion.kt

@@ -18,7 +18,7 @@ class JvmMetadataVersion(vararg numbers: Int) : BinaryVersion(*numbers) {
 
     companion object {
         @JvmField
-        val INSTANCE = JvmMetadataVersion(1, 1, 10)
+        val INSTANCE = JvmMetadataVersion(1, 1, 11)
 
         @JvmField
         val INVALID_VERSION = JvmMetadataVersion()

core/metadata/src/org/jetbrains/kotlin/metadata/builtins/BuiltInsBinaryVersion.kt

@@ -18,7 +18,7 @@ class BuiltInsBinaryVersion(vararg numbers: Int) : BinaryVersion(*numbers) {
 
     companion object {
         @JvmField
-        val INSTANCE = BuiltInsBinaryVersion(1, 0, 3)
+        val INSTANCE = BuiltInsBinaryVersion(1, 0, 4)
 
         @JvmField
         val INVALID_VERSION = BuiltInsBinaryVersion()