[Analysis API] Fix module provider for files from dependent sessions

Files coming from dependent sessions might be fully virtual, so there
won't be any backing 'VirtualFile'. However, they generally belong to
their original file's module.

analysis/analysis-api-standalone/analysis-api-standalone-base/src/org/jetbrains/kotlin/analysis/api/standalone/base/project/structure/KtStaticModuleProvider.kt

@@ -18,16 +18,18 @@ class KtStaticModuleProvider(
 ) : KtStaticProjectStructureProvider() {
     @OptIn(KtModuleStructureInternals::class)
     override fun getModule(element: PsiElement, contextualModule: KtModule?): KtModule {
-        val containingFileAsPsiFile = element.containingFile
-        val containingFileAsVirtualFile = containingFileAsPsiFile.virtualFile
-        if (containingFileAsVirtualFile.extension == BuiltInSerializerProtocol.BUILTINS_FILE_EXTENSION) {
+        // Unwrap context-dependent file copies coming from dependent sessions
+        val containingPsiFile = element.containingFile.originalFile
+
+        val containingVirtualFile = containingPsiFile.virtualFile
+        if (containingVirtualFile.extension == BuiltInSerializerProtocol.BUILTINS_FILE_EXTENSION) {
             return builtinsModule
         }
 
-        containingFileAsVirtualFile.analysisExtensionFileContextModule?.let { return it }
+        containingVirtualFile.analysisExtensionFileContextModule?.let { return it }
 
         projectStructure.binaryModules.firstOrNull { binaryModule ->
-            containingFileAsVirtualFile in binaryModule.contentScope
+            containingVirtualFile in binaryModule.contentScope
         }?.let { return it }
 
         return projectStructure.mainModules.firstOrNull { module ->
@@ -35,7 +37,7 @@ class KtStaticModuleProvider(
         }?.ktModule
             ?: throw KotlinExceptionWithAttachments("Cannot find KtModule; see the attachment for more details.")
                 .withAttachment(
-                    containingFileAsVirtualFile.path,
+                    containingVirtualFile.path,
                     allKtModules.joinToString(separator = System.lineSeparator()) { it.asDebugString() }
                 )
     }