Use a builder instead of boolean/option arguments

src/parse/session.rs

@@ -153,8 +153,6 @@ fn default_handler(
         ))
     };
     Handler::with_emitter(
-        true,
-        None,
         Box::new(SilentOnIgnoredFilesEmitter {
             has_non_ignorable_parser_errors: false,
             source_map,
@@ -162,7 +160,6 @@ fn default_handler(
             ignore_path_set,
             can_reset,
         }),
-        None,
     )
 }
 
@@ -234,7 +231,7 @@ impl ParseSess {
     }
 
     pub(crate) fn set_silent_emitter(&mut self) {
-        self.parse_sess.span_diagnostic = Handler::with_emitter(true, None, silent_emitter(), None);
+        self.parse_sess.span_diagnostic = Handler::with_emitter(silent_emitter());
     }
 
     pub(crate) fn span_to_filename(&self, span: Span) -> FileName {