Comments are being reordered by `-Zunpretty=normal`

After running rustc -Zunpretty=normal on a simple file (see below), I expected the output to match the original source code exactly.
However, a doc-comment and a regular comment were reordered in the output.
Is this expected behavior?

NB: If the // comment comes before the /// comment, then there is no reordering.

Original code:

/// comment 1
// comment 2
fn test() {}

Output of running rustc -Zunpretty=normal test.rs:

// comment 2
/// comment 1
fn test() {}

Meta

rustc --version --verbose:

rustc 1.98.0-nightly (57d06900f 2026-05-27)
binary: rustc
commit-hash: 57d06900fd7d9ee06d3a7f323bb77f17ab3cfaf8
commit-date: 2026-05-27
host: x86_64-unknown-linux-gnu
release: 1.98.0-nightly
LLVM version: 22.1.6

Start by reproducing the example with rustc -Zunpretty=normal and compare the input and output comment order. Then trace the compiler's pretty-printing and comment handling to determine whether the reordering is intended; done means the behavior is understood and covered by an appropriate regression test or documented as expected.