feat(L06): add control flow and program counter card

tests/task01_branch_compare_tb.sv

@@ -0,0 +1,22 @@
+module tb;
+    logic [31:0] lhs, rhs;
+    logic [2:0] funct3;
+    logic taken, illegal;
+    integer checks = 0;
+    string trace_file;
+    branch_compare dut (.*);
+    task automatic check(input logic [2:0] function_code, input logic expected);
+        funct3 = function_code; #1;
+        if (taken !== expected || illegal) $fatal(1, "FAIL f=%b taken=%b illegal=%b", function_code, taken, illegal);
+        checks += 1;
+    endtask
+    initial begin
+        if ($value$plusargs("trace=%s", trace_file)) begin $dumpfile(trace_file); $dumpvars(0, tb); end
+        lhs = 32'hffffffff; rhs = 1;
+        check(0,0); check(1,1); check(4,1); check(5,0); check(6,0); check(7,1);
+        funct3 = 2; #1;
+        if (!illegal || taken) $fatal(1, "FAIL illegal");
+        $display("PASS task01 conditions=%0d signed_lt=1 unsigned_lt=0 illegal=1", checks);
+        $finish;
+    end
+endmodule