Rollup merge of #92357 - GuillaumeGomez:fix-doc-comment-backline-removal, r=camelid

Fix invalid removal of newlines from doc comments

Fixes https://github.com/rust-lang/rust/issues/91201.

Before:

![Screenshot from 2021-12-28 17-02-11](https://user-images.githubusercontent.com/3050060/147585187-c8e67531-c1b4-457d-9d30-d5b44bf91fea.png)

After:

![Screenshot from 2021-12-28 17-02-25](https://user-images.githubusercontent.com/3050060/147585190-30aa0398-1fc7-4fe7-9e8b-5c475d4f9613.png)

r? `@camelid`

1 files changed, 0 insertions, 7 deletions

diff --git a/compiler/rustc_ast/src/util/comments.rs b/compiler/rustc_ast/src/util/comments.rs
index 80a06fa5943..0a391123dd3 100644
--- a/compiler/rustc_ast/src/util/comments.rs
+++ b/compiler/rustc_ast/src/util/comments.rs
@@ -34,18 +34,11 @@ pub fn beautify_doc_string(data: Symbol) -> Symbol {
             i += 1;
         }
 
-        while i < j && lines[i].trim().is_empty() {
-            i += 1;
-        }
         // like the first, a last line of all stars should be omitted
         if j > i && !lines[j - 1].is_empty() && lines[j - 1].chars().all(|c| c == '*') {
             j -= 1;
         }
 
-        while j > i && lines[j - 1].trim().is_empty() {
-            j -= 1;
-        }
-
         if i != 0 || j != lines.len() { Some((i, j)) } else { None }
     }