Make script infrastructure providers optional

compiler/psi/src/org/jetbrains/kotlin/psi/KtScript.java

@@ -30,6 +30,9 @@ import java.util.List;
 public class KtScript extends KtNamedDeclarationStub<KotlinScriptStub> implements KtDeclarationContainer {
     public KotlinScriptDefinition getKotlinScriptDefinition() {
         ScriptDefinitionProvider definitionsProvider = ScriptDefinitionProvider.Companion.getInstance(getProject());
+        if (definitionsProvider == null) {
+            throw new IllegalStateException("Unable to use KtScript: ScriptDefinitionProvider is not configured.");
+        }
         KotlinScriptDefinition definition = definitionsProvider.findScriptDefinition(getContainingKtFile().getName());
         return definition != null ? definition : definitionsProvider.getDefaultScriptDefinition();
     }

compiler/psi/src/org/jetbrains/kotlin/script/KotlinScriptDefinitionProvider.kt

@@ -37,7 +37,7 @@ interface ScriptDefinitionProvider {
     fun getKnownFilenameExtensions(): Sequence<String>
 
     companion object {
-        fun getInstance(project: Project): ScriptDefinitionProvider =
+        fun getInstance(project: Project): ScriptDefinitionProvider? =
             ServiceManager.getService(project, ScriptDefinitionProvider::class.java)
     }
 }
@@ -51,7 +51,7 @@ fun findScriptDefinition(file: VirtualFile, project: Project): KotlinScriptDefin
         return null
     }
 
-    val scriptDefinitionProvider = ScriptDefinitionProvider.getInstance(project)
+    val scriptDefinitionProvider = ScriptDefinitionProvider.getInstance(project) ?: return null
     val psiFile = PsiManager.getInstance(project).findFile(file)
     if (psiFile != null) {
         if (psiFile !is KtFile) return null

compiler/psi/src/org/jetbrains/kotlin/script/ScriptDependenciesProvider.kt

@@ -27,7 +27,7 @@ interface ScriptDependenciesProvider {
     fun getScriptDependencies(file: PsiFile) = getScriptDependencies(file.virtualFile ?: file.originalFile.virtualFile)
 
     companion object {
-        fun getInstance(project: Project): ScriptDependenciesProvider =
+        fun getInstance(project: Project): ScriptDependenciesProvider? =
             ServiceManager.getService(project, ScriptDependenciesProvider::class.java)
     }
 }