Implement automatic loading of .main.kts scripts support

also fix discovery from ScriptDefinitionsProvider

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

@@ -100,13 +100,15 @@ interface KotlinPaths {
         CoroutinesCore(PathUtil.KOTLINX_COROUTINES_CORE_NAME),
         KotlinDaemon(PathUtil.KOTLIN_DAEMON_NAME),
         Ktor(PathUtil.KTOR_NAME),
+        MainKts(PathUtil.MAIN_KTS_NAME)
     }
 
     // TODO: Maybe we need separate classpaths for compilers with and without the daemon
     enum class ClassPaths(val contents: List<Jar> = emptyList()) {
         Empty(),
         Compiler(Jar.Compiler, Jar.StdLib, Jar.Reflect, Jar.ScriptRuntime, Jar.Trove4j, Jar.KotlinDaemon, Jar.Ktor),
-        CompilerWithScripting(Compiler, Jar.ScriptingPlugin, Jar.ScriptingImpl, Jar.ScriptingLib, Jar.ScriptingJvmLib)
+        CompilerWithScripting(Compiler, Jar.ScriptingPlugin, Jar.ScriptingImpl, Jar.ScriptingLib, Jar.ScriptingJvmLib),
+        MainKts(Jar.MainKts, Jar.ScriptRuntime, Jar.StdLib, Jar.Reflect)
         ;
 
         constructor(vararg jars: Jar) : this(jars.asList())

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

@@ -79,6 +79,7 @@ object PathUtil {
     const val KOTLIN_SCRIPTING_COMPILER_IMPL_JAR = "$KOTLIN_SCRIPTING_COMPILER_IMPL_NAME.jar"
     const val JS_ENGINES_NAME = "js.engines"
     const val JS_ENGINES_JAR = "$JS_ENGINES_NAME.jar"
+    const val MAIN_KTS_NAME = "kotlin-main-kts"
 
     val KOTLIN_SCRIPTING_PLUGIN_CLASSPATH_JARS = arrayOf(
         KOTLIN_SCRIPTING_COMPILER_PLUGIN_JAR, KOTLIN_SCRIPTING_COMPILER_IMPL_JAR,