Strip last backline from non-rust code examples

Author: GuillaumeGomez

Diff for: src/librustdoc/html/markdown.rs

@@ -261,7 +261,9 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for CodeBlocks<'_, 'a, I> {
                                  </pre>\
                              </div>",
                                 added_classes = added_classes.join(" "),
-                                text = Escape(&original_text),
+                                text = Escape(
+                                    original_text.strip_suffix('\n').unwrap_or(&original_text)
+                                ),
                             )
                             .into(),
                         ));

Diff for: src/librustdoc/html/markdown/tests.rs

@@ -524,15 +524,13 @@ fn test_ascii_with_prepending_hashtag() {
 ####.###..#....#....#..#.
 #..#.#....#....#....#..#.
 #..#.#....#....#....#..#.
-#..#.####.####.####..##..
-</code></pre></div>",
+#..#.####.####.####..##..</code></pre></div>",
     );
     t(
         r#"```markdown
 # hello
 ```"#,
         "<div class=\"example-wrap\"><pre class=\"language-markdown\"><code>\
-# hello
-</code></pre></div>",
+# hello</code></pre></div>",
     );
 }