Extract script descriptor creation to scripting plugin

plugins/scripting/scripting-cli/src/org/jetbrains/kotlin/scripting/compiler/plugin/ScriptingCompilerConfigurationExtension.kt

@@ -18,6 +18,7 @@ import org.jetbrains.kotlin.config.CompilerConfiguration
 import org.jetbrains.kotlin.config.JVMConfigurationKeys
 import org.jetbrains.kotlin.extensions.CompilerConfigurationExtension
 import org.jetbrains.kotlin.idea.KotlinFileType
+import org.jetbrains.kotlin.resolve.extensions.SyntheticResolveExtension
 import org.jetbrains.kotlin.script.ScriptDefinitionProvider
 import org.jetbrains.kotlin.script.ScriptDependenciesProvider
 import org.jetbrains.kotlin.script.ScriptReportSink
@@ -105,6 +106,7 @@ class ScriptingCompilerConfigurationComponentRegistrar : ComponentRegistrar {
             ScriptDependenciesProvider::class.java,
             CliScriptDependenciesProvider(project)
         )
+        SyntheticResolveExtension.registerExtension(project, ScriptingResolveExtension())
 
         val messageCollector = configuration.get(CLIConfigurationKeys.MESSAGE_COLLECTOR_KEY)
         if (messageCollector != null) {

plugins/scripting/scripting-cli/src/org/jetbrains/kotlin/scripting/compiler/plugin/scriptingResolveExtension.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.scripting.compiler.plugin
+
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.descriptors.PackageFragmentDescriptor
+import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.resolve.extensions.SyntheticResolveExtension
+import org.jetbrains.kotlin.resolve.lazy.LazyClassContext
+import org.jetbrains.kotlin.resolve.lazy.ResolveSession
+import org.jetbrains.kotlin.resolve.lazy.data.KtScriptInfo
+import org.jetbrains.kotlin.resolve.lazy.declarations.PackageMemberDeclarationProvider
+import org.jetbrains.kotlin.resolve.lazy.descriptors.LazyScriptDescriptor
+
+class ScriptingResolveExtension : SyntheticResolveExtension {
+    override fun generateSyntheticClasses(
+        thisDescriptor: PackageFragmentDescriptor,
+        name: Name,
+        ctx: LazyClassContext,
+        declarationProvider: PackageMemberDeclarationProvider,
+        result: MutableSet<ClassDescriptor>
+    ) {
+        declarationProvider.getClassOrObjectDeclarations(name).mapNotNullTo(result) {
+            if (it is KtScriptInfo) {
+                LazyScriptDescriptor(ctx as ResolveSession, thisDescriptor, name, it)
+            } else null
+        }
+
+        super.generateSyntheticClasses(thisDescriptor, name, ctx, declarationProvider, result)
+    }
+}