Avoid using reflected types in the scripting API

since it causes numerous classloading issues. Using the wrapping types
and reload them in the proper context when needed.
Note: this version supports only classes, but the wrapping type could
be extended to support other types in the future.
+ numerous fixes related to proper loading and handling of the templates.

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/K2JVMCompiler.kt

@@ -235,9 +235,11 @@ class K2JVMCompiler : CLICompiler<K2JVMCompilerArguments>() {
             if (!explicitOrLoadedScriptingPlugin) {
                 val libPath = paths?.libPath?.takeIf { it.exists() } ?: File(".")
                 with(PathUtil) {
-                    val jars = arrayOf(KOTLIN_SCRIPTING_COMPILER_PLUGIN_JAR, KOTLIN_SCRIPTING_COMMON_JAR, KOTLIN_SCRIPTING_JVM_JAR)
-                        .mapNotNull { File(libPath, it).takeIf { it.exists() }?.canonicalPath }
-                    if (jars.size == 3) {
+                    val jars = arrayOf(
+                        KOTLIN_SCRIPTING_COMPILER_PLUGIN_JAR, KOTLIN_SCRIPTING_COMMON_JAR,
+                        KOTLIN_SCRIPTING_JVM_JAR, KOTLIN_SCRIPTING_MISC_JAR
+                    ).mapNotNull { File(libPath, it).takeIf { it.exists() }?.canonicalPath }
+                    if (jars.size == 4) {
                         pluginClasspaths = jars + pluginClasspaths
                     }
                 }

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/plugins/PluginCliParser.kt

@@ -27,6 +27,7 @@ import org.jetbrains.kotlin.compiler.plugin.*
 import org.jetbrains.kotlin.config.CompilerConfiguration
 import java.io.File
 import java.net.URL
+import java.net.URLClassLoader
 import java.util.*
 
 object PluginCliParser {

compiler/tests/org/jetbrains/kotlin/codegen/AbstractCustomScriptCodegenTest.kt

@@ -15,9 +15,9 @@ import org.jetbrains.kotlin.test.InTextDirectivesUtils
 import org.jetbrains.kotlin.test.TestJdkKind
 import org.junit.Assert
 import java.io.File
-import kotlin.reflect.full.starProjectedType
 import kotlin.script.experimental.annotations.KotlinScript
 import kotlin.script.experimental.annotations.KotlinScriptDefaultCompilationConfiguration
+import kotlin.script.experimental.api.KotlinType
 import kotlin.script.experimental.api.ScriptCompileConfigurationProperties
 import kotlin.script.experimental.util.TypedKey
 
@@ -32,7 +32,7 @@ abstract class AbstractCustomScriptCodegenTest : CodegenTestCase() {
 
     override fun updateConfiguration(configuration: CompilerConfiguration) {
         if (scriptDefinitions.isNotEmpty()) {
-            configureScriptDefinitions(scriptDefinitions, configuration, MessageCollector.NONE, emptyMap())
+            configureScriptDefinitions(scriptDefinitions, configuration, this::class.java.classLoader, MessageCollector.NONE, emptyMap())
         }
 
         configuration.addJvmClasspathRoots(additionalDependencies.orEmpty())
@@ -116,7 +116,7 @@ abstract class AbstractCustomScriptCodegenTest : CodegenTestCase() {
 
 object TestScriptWithReceiversConfiguration : ArrayList<Pair<TypedKey<*>, Any?>>(
     listOf(
-        ScriptCompileConfigurationProperties.scriptImplicitReceivers to listOf(String::class.starProjectedType)
+        ScriptCompileConfigurationProperties.scriptImplicitReceivers to listOf(KotlinType(String::class))
     )
 )
 
@@ -127,7 +127,7 @@ abstract class TestScriptWithReceivers
 
 object TestScriptWithSimpleEnvVarsConfiguration : ArrayList<Pair<TypedKey<*>, Any?>>(
     listOf(
-        ScriptCompileConfigurationProperties.contextVariables to mapOf("stringVar1" to String::class.starProjectedType)
+        ScriptCompileConfigurationProperties.contextVariables to mapOf("stringVar1" to KotlinType(String::class))
     )
 )
 

compiler/tests/org/jetbrains/kotlin/generators/tests/GenerateCompilerTests.kt

@@ -27,6 +27,7 @@ import org.jetbrains.kotlin.cli.AbstractCliTest
 import org.jetbrains.kotlin.codegen.*
 import org.jetbrains.kotlin.codegen.defaultConstructor.AbstractDefaultArgumentsReflectionTest
 import org.jetbrains.kotlin.codegen.flags.AbstractWriteFlagsTest
+import org.jetbrains.kotlin.codegen.AbstractCustomScriptCodegenTest
 import org.jetbrains.kotlin.codegen.ir.AbstractIrBlackBoxCodegenTest
 import org.jetbrains.kotlin.codegen.ir.AbstractIrBlackBoxInlineCodegenTest
 import org.jetbrains.kotlin.codegen.ir.AbstractIrCompileKotlinAgainstInlineKotlinTest

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

@@ -59,6 +59,7 @@ object PathUtil {
     const val KOTLIN_JAVA_SCRIPT_RUNTIME_JAR = "kotlin-script-runtime.jar"
     const val KOTLIN_SCRIPTING_COMMON_JAR = "kotlin-scripting-common.jar"
     const val KOTLIN_SCRIPTING_JVM_JAR = "kotlin-scripting-jvm.jar"
+    const val KOTLIN_SCRIPTING_MISC_JAR = "kotlin-scripting-misc.jar"
     const val KOTLIN_SCRIPTING_COMPILER_PLUGIN_JAR = "kotlin-scripting-compiler.jar"
 
     const val KOTLIN_TEST_NAME = "kotlin-test"