KT-60749 Scripting: default definition as a fallback

This commit effectively reverts changes made in the scope of KT-60193,
namely c9eebffb and 2d50bd68.

^KT-60749 fixed

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

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.scripting.definitions
 import com.intellij.ide.highlighter.JavaFileType
 import com.intellij.injected.editor.VirtualFileWindow
 import com.intellij.openapi.application.ApplicationManager
+import com.intellij.openapi.diagnostic.Logger
 import com.intellij.openapi.fileTypes.FileTypeRegistry
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.util.Computable
@@ -23,6 +24,7 @@ import kotlin.contracts.ExperimentalContracts
 import kotlin.contracts.contract
 import kotlin.script.experimental.api.SourceCode
 
+
 inline fun <T> runReadAction(crossinline runnable: () -> T): T {
     return ApplicationManager.getApplication().runReadAction(Computable { runnable() })
 }
@@ -61,10 +63,15 @@ fun VirtualFile.findScriptDefinition(project: Project): ScriptDefinition? {
     return findScriptDefinition(project, VirtualFileScriptSource(this))
 }
 
-fun findScriptDefinition(project: Project, script: SourceCode): ScriptDefinition? {
+fun findScriptDefinition(project: Project, script: SourceCode): ScriptDefinition {
     val scriptDefinitionProvider = ScriptDefinitionProvider.getInstance(project)
         ?: error("Unable to get script definition: ScriptDefinitionProvider is not configured.")
     return scriptDefinitionProvider.findDefinition(script)
+        ?: scriptDefinitionProvider.getDefaultDefinition()
+            .also {
+                Logger.getInstance("org.jetbrains.kotlin.scripting.definitions")
+                    .debug("Default definition is used for ${script.locationId}")
+            }
 }
 
 private const val JAVA_CLASS_FILE_TYPE_DOT_DEFAULT_EXTENSION = ".class"