Add prop EngineName to abstract class LuaLibraries

src/BizHawk.Client.Common/lua/CommonLibs/EmulationLuaLibrary.cs

@@ -102,9 +102,6 @@ namespace BizHawk.Client.Common
 		public string GetBoardName() => APIs.Emulation.GetBoardName();
 
 		[LuaMethod("getluacore", "returns the name of the Lua core currently in use")]
-		public string GetLuaBackend()
-		{
-			return Lua.WhichLua;
-		}
+		public string GetLuaBackend() => _luaLibsImpl.EngineName;
 	}
 }

src/BizHawk.Client.Common/lua/LuaLibraries.cs

@@ -10,6 +10,9 @@ namespace BizHawk.Client.Common
 	public abstract class LuaLibraries
 	{
 		public readonly LuaDocumentation Docs = new LuaDocumentation();
+
+		public abstract string EngineName { get; }
+
 		public abstract LuaFunctionList RegisteredFunctions { get; }
 		public abstract GuiLuaLibrary GuiLibrary { get; }
 		protected readonly Dictionary<Type, LuaLibraryBase> Libraries = new Dictionary<Type, LuaLibraryBase>();

src/BizHawk.Client.EmuHawk/tools/Lua/UnixLuaLibraries.cs

@@ -10,6 +10,8 @@ namespace BizHawk.Client.EmuHawk
 	/// </summary>
 	public sealed class UnixLuaLibraries : LuaLibraries
 	{
+		public override string EngineName => null;
+
 		public override void CallExitEvent(LuaFile lf)
 		{
 		}

src/BizHawk.Client.EmuHawk/tools/Lua/Win32LuaLibraries.cs

@@ -116,6 +116,8 @@ namespace BizHawk.Client.EmuHawk
 
 		private EmulationLuaLibrary EmulationLuaLibrary => (EmulationLuaLibrary)Libraries[typeof(EmulationLuaLibrary)];
 
+		public override string EngineName => Lua.WhichLua;
+
 		public override GuiLuaLibrary GuiLibrary => (GuiLuaLibrary) Libraries[typeof(GuiLuaLibrary)];
 
 		private static void LogToLuaConsole(object outputs) => _logToLuaConsoleCallback(new[] { outputs });