Rollup merge of #47407 - gaurikholkar:master, r=estebank

fix mispositioned span

This fixes #47377

The output now looks like this
```
error[E0369]: binary operation `+` cannot be applied to type `&str`
 --> h.rs:3:11
  |
3 |     let _a = b + ", World!";
  |              ^^^^^^^^^^^^^^ `+` can't be used to concatenate two `&str` strings
help: `to_owned()` can be used to create an owned `String` from a string reference. String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left
  |
3 |     let _a = b.to_owned() + ", World!";
  |              ^^^^^^^^^

error: aborting due to previous error
```
For the case when emojis are involved,  it gives the new output for proper indentation.
But for an indentation as follows,
```
fn main() {
let b = "hello";
    let _a = b + ", World!";
}
```
it still mispositions the span
```
3 |     println!("🦀🦀🦀🦀🦀"); let _a = b + ", World!";
  |                                           ^^^^^^^^^^^^^^ `+` can't be used to concatenate two `&str` strings
  |
3 |     println!("🦀🦀🦀🦀🦀"); let _a = b.to_owned() + ", World!";
  |                                           ^^^^^^^
error: aborting due to previous erro
```

cc @estebank  @est31

1 files changed, 2 insertions, 2 deletions

diff --git a/src/librustc_errors/emitter.rs b/src/librustc_errors/emitter.rs
index 1c3d4af9e18..58f851aea38 100644
--- a/src/librustc_errors/emitter.rs
+++ b/src/librustc_errors/emitter.rs
@@ -1187,8 +1187,8 @@ impl EmitterWriter {
                     let sub_len = parts[0].snippet.trim().chars().fold(0, |acc, ch| {
                         acc + unicode_width::UnicodeWidthChar::width(ch).unwrap_or(0)
                     });
-                    let underline_start = span_start_pos.col.0 + start;
-                    let underline_end = span_start_pos.col.0 + start + sub_len;
+                    let underline_start = span_start_pos.col_display + start;
+                    let underline_end = span_start_pos.col_display + start + sub_len;
                     for p in underline_start..underline_end {
                         buffer.putc(row_num,
                                     max_line_num_len + 3 + p,