Added ModelSim folder (and have to add files into it as to allow for different testbench code)

tests/lu_tb.sv

@@ -1,13 +1,13 @@
 `include "lu.sv"
 
-module lu_tb #(W=8)();
+module lu_tb #(parameter W=4)();
     logic [1:0] op;
     logic [W-1:0] A;
     logic [W-1:0] B;
     logic [W-1:0] C;
     logic [W-1:0] C_exp[16];
 
-    lu #(W) dut();
+    lu #(W/2) dut();
 
     integer error_count;
     initial begin
@@ -56,4 +56,4 @@ module lu_tb #(W=8)();
         if (error_count == 0) $display("\x1b[38;5;10mAll LU tests passing\x1b[m");
         else $display("\x1b[38;5;9m%0d LU test(s) failing\x1b[m", error_count);
     end
-endmodule
+endmodule