Address review comments

Co-Authored-By: Mazdak Farrokhzad <twingoow@gmail.com>

src/librustc/session/config.rs

@@ -227,14 +227,14 @@ pub fn extension(&self) -> &'static str {
     }
 }
 
-/// The type of diagnostics output to generate
+/// The type of diagnostics output to generate.
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum ErrorOutputType {
     /// Output meant for the consumption of humans.
     HumanReadable(HumanReadableErrorType),
     /// Output that's consumed by other tools such as `rustfix` or the `RLS`.
     Json {
-        /// Render the JSON in a human readable way (with indents and newlines)
+        /// Render the JSON in a human readable way (with indents and newlines).
         pretty: bool,
         /// The JSON output includes a `rendered` field that includes the rendered
         /// human output.

src/librustc_errors/diagnostic_builder.rs

@@ -348,7 +348,7 @@ pub fn new(handler: &'a Handler, level: Level, message: &str) -> DiagnosticBuild
 
     /// Convenience function for internal use, clients should use one of the
     /// struct_* methods on Handler.
-    pub(crate) fn new_with_code(handler: &'a Handler,
+    crate fn new_with_code(handler: &'a Handler,
                          level: Level,
                          code: Option<DiagnosticId>,
                          message: &str)

src/librustc_errors/lib.rs

@@ -1,9 +1,10 @@
-//! Diagnostics creation and emission for rustc
+//! Diagnostics creation and emission for `rustc`.
 //!
 //! This module contains the code for creating and emitting diagnostics.
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
 
+#![feature(crate_visibility_modifier)]
 #![allow(unused_attributes)]
 #![cfg_attr(unix, feature(libc))]
 #![feature(nll)]