Auto merge of #86982 - GuillaumeGomez:rollup-7sbye3c, r=GuillaumeGomez

Rollup of 8 pull requests

Successful merges:

 - #84961 (Rework SESSION_GLOBALS API)
 - #86726 (Use diagnostic items instead of lang items for rfc2229 migrations)
 - #86789 (Update BTreeSet::drain_filter documentation)
 - #86838 (Checking that function is const if marked with rustc_const_unstable)
 - #86903 (Fix small headers display)
 - #86913 (Document rustdoc with `--document-private-items`)
 - #86957 (Update .mailmap file)
 - #86971 (mailmap: Add alternative addresses for myself)

Failed merges:

 - #86869 (Account for capture kind in auto traits migration)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 1 insertions, 6 deletions

diff --git a/compiler/rustc_errors/src/json/tests.rs b/compiler/rustc_errors/src/json/tests.rs
index e69e868c8ed..d055937ac36 100644
--- a/compiler/rustc_errors/src/json/tests.rs
+++ b/compiler/rustc_errors/src/json/tests.rs
@@ -39,16 +39,11 @@ impl<T: Write> Write for Shared<T> {
     }
 }
 
-fn with_default_session_globals(f: impl FnOnce()) {
-    let session_globals = rustc_span::SessionGlobals::new(rustc_span::edition::DEFAULT_EDITION);
-    rustc_span::SESSION_GLOBALS.set(&session_globals, f);
-}
-
 /// Test the span yields correct positions in JSON.
 fn test_positions(code: &str, span: (u32, u32), expected_output: SpanTestData) {
     let expected_output = TestData { spans: vec![expected_output] };
 
-    with_default_session_globals(|| {
+    rustc_span::create_default_session_globals_then(|| {
         let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
         sm.new_source_file(Path::new("test.rs").to_owned().into(), code.to_owned());