diags: fix reporting lines on crlf files (#1036)

Author: BrettMayson

libs/workspace/src/reporting/files.rs

@@ -56,7 +56,7 @@ impl WorkspaceFiles {
             .or_insert_with(|| {
                 let source = file_id.read_to_string().unwrap_or_default();
                 let line_starts = source
-                    .lines()
+                    .split('\n')
                     .scan(0, |pos, line| {
                         let start = *pos;
                         *pos += line.len() + 1;