Add a ChangeInfo.

Author: khuey

src/bootstrap/src/utils/change_tracker.rs

@@ -220,4 +220,9 @@ pub const CONFIG_CHANGE_HISTORY: &[ChangeInfo] = &[
         severity: ChangeSeverity::Warning,
         summary: "For tarball sources, default value for `rust.channel` will be taken from `src/ci/channel` file.",
     },
+    ChangeInfo {
+        change_id: 125642,
+        severity: ChangeSeverity::Info,
+        summary: "New option `llvm-libzstd` to control whether llvm is built with zstd support.",
+    },
 ];