Adds line number substitution in test cases

Expanded generate_code.pl to substitute !LINE_NO! in test cases.
diff --git a/tests/scripts/generate_code.pl b/tests/scripts/generate_code.pl
index 93c003b..9c59591 100755
--- a/tests/scripts/generate_code.pl
+++ b/tests/scripts/generate_code.pl
@@ -95,6 +95,8 @@
         $line = $line."#line $index \"$test_case_file\"\n";
     }
 
+    $line =~ s/!LINE_NO!/$index/;
+
     $test_cases = $test_cases.$line;
     $index++;
 }