[LL API] Provide customizable default language version settings

analysis/project-structure/src/org/jetbrains/kotlin/analysis/project/structure/ProjectStructureProvider.kt

@@ -7,6 +7,8 @@ package org.jetbrains.kotlin.analysis.project.structure
 
 import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.config.LanguageVersionSettings
+import org.jetbrains.kotlin.config.LanguageVersionSettingsImpl
 
 public abstract class ProjectStructureProvider {
     /**
@@ -24,6 +26,19 @@ public abstract class ProjectStructureProvider {
      */
     public abstract fun getModule(element: PsiElement, contextualModule: KtModule?): KtModule
 
+    /**
+     * Project-global [LanguageVersionSettings]. For source modules lacking [LanguageVersionSettings]
+     * (such as [KtNotUnderContentRootModule]), the default settings apply.
+     */
+    public open val globalLanguageVersionSettings: LanguageVersionSettings
+        get() = LanguageVersionSettingsImpl.DEFAULT
+
+    /**
+     * Project-global [LanguageVersionSettings] for [KtLibraryModule]s and [KtLibrarySourceModule]s.
+     */
+    public open val libraryLanguageVersionSettings: LanguageVersionSettings
+        get() = globalLanguageVersionSettings
+
     public companion object {
         public fun getInstance(project: Project): ProjectStructureProvider {
             return project.getService(ProjectStructureProvider::class.java)