Remove TODOs (they're done)

src/librustc_mir/graphviz.rs

@@ -173,5 +173,3 @@ fn node(block: BasicBlock) -> String {
 fn escape<T: Debug>(t: &T) -> String {
     dot::escape_html(&format!("{:?}", t))
 }
-
-// TODO manually test

src/librustc_mir/pretty.rs

@@ -355,5 +355,3 @@ fn write_temp_decls(mir: &Mir, w: &mut Write) -> io::Result<()> {
 
     Ok(())
 }
-
-// TODO manually test