Rollup merge of #76794 - richkadel:graphviz-font, r=ecstatic-morse

Make graphviz font configurable

Alternative to PR #76776.

To change the graphviz output to use an alternative `fontname` value,
add a command line option like: `rustc --graphviz-font=monospace`.

r? @ecstatic-morse

compiler/rustc_mir/src/dataflow/framework/engine.rs

@@ -306,7 +306,8 @@ where
     let mut buf = Vec::new();
 
     let graphviz = graphviz::Formatter::new(body, def_id, results, style);
-    let mut render_opts = vec![dot::RenderOption::Monospace];
+    let mut render_opts =
+        vec![dot::RenderOption::Fontname(tcx.sess.opts.debugging_opts.graphviz_font.clone())];
     if tcx.sess.opts.debugging_opts.graphviz_dark_mode {
         render_opts.push(dot::RenderOption::DarkTheme);
     }