GDExtension: Use loader to check if the library exists.

core/extension/gdextension_library_loader.cpp

@@ -259,6 +259,10 @@ bool GDExtensionLibraryLoader::has_library_changed() const {
 	return false;
 }
 
+bool GDExtensionLibraryLoader::library_exists() const {
+	return FileAccess::exists(resource_path);
+}
+
 Error GDExtensionLibraryLoader::parse_gdextension_file(const String &p_path) {
 	resource_path = p_path;
 

core/extension/gdextension_library_loader.h

@@ -77,6 +77,7 @@ public:
 	virtual void close_library() override;
 	virtual bool is_library_open() const override;
 	virtual bool has_library_changed() const override;
+	virtual bool library_exists() const override;
 
 	Error parse_gdextension_file(const String &p_path);
 };

core/extension/gdextension_loader.h

@@ -42,6 +42,7 @@ public:
 	virtual void close_library() = 0;
 	virtual bool is_library_open() const = 0;
 	virtual bool has_library_changed() const = 0;
+	virtual bool library_exists() const = 0;
 };
 
 #endif // GDEXTENSION_LOADER_H

core/extension/gdextension_manager.cpp

@@ -302,7 +302,8 @@ bool GDExtensionManager::ensure_extensions_loaded(const HashSet<String> &p_exten
 	for (const String &loaded_extension : loaded_extensions) {
 		if (!p_extensions.has(loaded_extension)) {
 			// The extension may not have a .gdextension file.
-			if (!FileAccess::exists(loaded_extension)) {
+			const Ref<GDExtension> extension = GDExtensionManager::get_singleton()->get_extension(loaded_extension);
+			if (!extension->get_loader()->library_exists()) {
 				extensions_removed.push_back(loaded_extension);
 			}
 		}