Lua bit.checkbit() function, returns if a specified bit is on/off.

BizHawk.Client.Common/lua/EmuLuaLibrary.Bit.cs

@@ -1,4 +1,5 @@
-namespace BizHawk.Client.Common
+using System;
+namespace BizHawk.Client.Common
 {
 	public class BitLuaLibrary : LuaLibraryBase
 	{
@@ -17,6 +18,7 @@
 					"rol",
 					"ror",
 					"rshift",
+					"check",
 				};
 			}
 		}
@@ -62,5 +64,11 @@
 		{
 			return (uint)(LuaInt(val) >> LuaInt(amt));
 		}
+
+		public static bool bit_check(object num, object pos)
+		{
+			var value = Convert.ToInt64(LuaLong(num));
+			return (value & (1 << (int)(LuaInt(pos)))) != 0;
+		}
 	}
 }