Improve class name generation for scripts and REPL snippets

- allow to override default name/scheme
- implement host/engine specific names for jsr223 to avoid classloading
  clashes (also fix "eval in eval" test)

plugins/scripting/scripting-compiler-impl/src/org/jetbrains/kotlin/scripting/definitions/ScriptDefinition.kt

@@ -31,6 +31,7 @@ abstract class ScriptDefinition : UserDataHolderBase() {
     abstract fun isScript(file: File): Boolean
     abstract val fileExtension: String
     abstract val name: String
+    open val defaultClassName: String = "Script"
     // TODO: used in settings, find out the reason and refactor accordingly
     abstract val definitionId: String
 
@@ -138,6 +139,9 @@ abstract class ScriptDefinition : UserDataHolderBase() {
                 compilationConfiguration[ScriptCompilationConfiguration.displayName]?.takeIf { it.isNotBlank() }
                     ?: compilationConfiguration[ScriptCompilationConfiguration.baseClass]!!.typeName.substringAfterLast('.')
 
+        override val defaultClassName: String
+            get() = compilationConfiguration[ScriptCompilationConfiguration.defaultIdentifier] ?: super.defaultClassName
+
         override val definitionId: String get() = compilationConfiguration[ScriptCompilationConfiguration.baseClass]!!.typeName
 
         override val contextClassLoader: ClassLoader? by lazy {

plugins/scripting/scripting-compiler-impl/src/org/jetbrains/kotlin/scripting/resolve/refineCompilationConfiguration.kt

@@ -291,7 +291,7 @@ fun SourceCode.getVirtualFile(definition: ScriptDefinition): VirtualFile {
         val vFile = LocalFileSystem.getInstance().findFileByIoFile(file)
         if (vFile != null) return vFile
     }
-    val scriptName = withCorrectExtension(name ?: "script", definition.fileExtension)
+    val scriptName = withCorrectExtension(name ?: definition.defaultClassName, definition.fileExtension)
     val scriptPath = when (this) {
         is FileScriptSource -> file.path
         is ExternalSourceCode -> externalLocation.toString()

plugins/scripting/scripting-compiler/src/org/jetbrains/kotlin/scripting/compiler/plugin/repl/GenericReplCompiler.kt

@@ -109,7 +109,6 @@ open class GenericReplCompiler(
                 CompilationErrorHandler.THROW_EXCEPTION
             )
 
-            val generatedClassname = makeScriptBaseName(codeLine)
             compilerState.history.push(LineId(codeLine), scriptDescriptor)
 
             val classes = generationState.factory.asList().map { CompiledClassData(it.relativePath, it.asByteArray()) }
@@ -117,7 +116,7 @@ open class GenericReplCompiler(
             return ReplCompileResult.CompiledClasses(
                 LineId(codeLine),
                 compilerState.history.map { it.id },
-                generatedClassname,
+                scriptDescriptor.name.identifier,
                 classes,
                 generationState.scriptSpecific.resultFieldName != null,
                 classpathAddendum ?: emptyList(),