[JS IR BE] Load builtins from code to runtime

Bypass builtins deserialization mechanism in legacy JS backend and load
bultins direcly as kotlin code.

This way we won't have separated IR declarations for Enum, Char, Long

Some "native" builtins are implemented in libraries/stdlib/js/irRuntime/builtins/
Other builtins are moved by MoveExternalDeclarationsToSeparatePlace and
used only in compile-time

js/js.tests/test/org/jetbrains/kotlin/js/test/BasicIrBoxTest.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.js.test
 
 import org.jetbrains.kotlin.config.*
+import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
 import org.jetbrains.kotlin.ir.backend.js.Result
 import org.jetbrains.kotlin.ir.backend.js.compile
 import org.jetbrains.kotlin.js.config.JSConfigurationKeys
@@ -13,6 +14,7 @@ import org.jetbrains.kotlin.js.config.JsConfig
 import org.jetbrains.kotlin.js.facade.MainCallParameters
 import org.jetbrains.kotlin.js.facade.TranslationUnit
 import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.test.KotlinTestUtils
 import org.jetbrains.kotlin.test.TargetBackend
 import java.io.File
 
@@ -112,7 +114,8 @@ abstract class BasicIrBoxTest(
             config.configuration,
             FqName((testPackage?.let { "$it." } ?: "") + testFunction),
             dependencies,
-            irDependencies
+            irDependencies,
+            runtimeResult.moduleDescriptor as ModuleDescriptorImpl
         )
 
         compilationCache[outputFile.name.replace(".js", ".meta.js")] = result

js/js.tests/test/org/jetbrains/kotlin/js/test/JsIrTestRuntime.kt

@@ -5,6 +5,7 @@
 
 package org.jetbrains.kotlin.js.test
 
+import org.jetbrains.kotlin.test.KotlinTestUtils
 import java.io.File
 
 private const val runtimeDir = "js/js.translator/testData/out/irBox"
@@ -26,6 +27,29 @@ enum class JsIrTestRuntime(
     )
 }
 
+// Required to compile native builtins with the rest of runtime
+private const val builtInsHeader = """@file:Suppress(
+    "NON_ABSTRACT_FUNCTION_WITH_NO_BODY",
+    "MUST_BE_INITIALIZED_OR_BE_ABSTRACT",
+    "EXTERNAL_TYPE_EXTENDS_NON_EXTERNAL_TYPE",
+    "PRIMARY_CONSTRUCTOR_DELEGATION_CALL_EXPECTED",
+    "WRONG_MODIFIER_TARGET"
+)
+"""
+
+// Native builtins that were not implemented in JS IR runtime
+private val unimplementedNativeBuiltInsDir = KotlinTestUtils.tmpDir("unimplementedBuiltins").also { tmpDir ->
+    val allBuiltins = listOfKtFilesFrom("core/builtins/native/kotlin").map { File(it).name }
+    val implementedBuiltIns = listOfKtFilesFrom("libraries/stdlib/js/irRuntime/builtins/").map { File(it).name }
+    val unimplementedBuiltIns = allBuiltins - implementedBuiltIns
+    for (filename in unimplementedBuiltIns) {
+        val originalFile = File("core/builtins/native/kotlin", filename)
+        val newFile = File(tmpDir, filename)
+        val sourceCode = builtInsHeader + originalFile.readText()
+        newFile.writeText(sourceCode)
+    }
+}
+
 private val fullRuntimeSources = listOfKtFilesFrom(
     "core/builtins/src/kotlin",
     "libraries/stdlib/common/src",
@@ -36,15 +60,8 @@ private val fullRuntimeSources = listOfKtFilesFrom(
     "libraries/stdlib/js/runtime",
     "libraries/stdlib/unsigned",
 
-    "core/builtins/native/kotlin/Annotation.kt",
-    "core/builtins/native/kotlin/Number.kt",
-    "core/builtins/native/kotlin/Comparable.kt",
-    "core/builtins/native/kotlin/Collections.kt",
-    "core/builtins/native/kotlin/Iterator.kt",
-    "core/builtins/native/kotlin/CharSequence.kt",
-
     "core/builtins/src/kotlin/Unit.kt",
-
+    unimplementedNativeBuiltInsDir.path,
     BasicBoxTest.COMMON_FILES_DIR_PATH
 ) - listOfKtFilesFrom(
     "libraries/stdlib/common/src/kotlin/JvmAnnotationsH.kt",
@@ -102,10 +119,6 @@ private val fullRuntimeSources = listOfKtFilesFrom(
 
 val reducedRuntimeSources = fullRuntimeSources - listOfKtFilesFrom(
     "libraries/stdlib/unsigned",
-    "core/builtins/src/kotlin/reflect/KParameter.kt",
-    "core/builtins/src/kotlin/reflect/KType.kt",
-    "core/builtins/src/kotlin/reflect/KTypeParameter.kt",
-    "core/builtins/src/kotlin/reflect/KVisibility.kt",
     "libraries/stdlib/common/src/generated/_Arrays.kt",
     "libraries/stdlib/common/src/generated/_Collections.kt",
     "libraries/stdlib/common/src/generated/_Maps.kt",