Add --rustc flag

Author: blyxyas

src/driver.rs

@@ -281,6 +281,7 @@ fn help_message() -> &'static str {
 <green,bold>Common options:</>
     <cyan,bold>-h</>, <cyan,bold>--help</>               Print this message
     <cyan,bold>-V</>, <cyan,bold>--version</>            Print version info and exit
+    <cyan,bold>--rustc</>                                Pass all arguments to <cyan>rustc</>
 
 <green,bold>Allowing / Denying lints</>
 You can use tool lints to allow or deny lints from your code, e.g.: