Explicitly call `emit_stashed_diagnostics`.

Commit 72b172b in #121206 changed things so that
`emit_stashed_diagnostics` is only called from `run_compiler`. But
rustfmt doesn't use `run_compiler`, so it needs to call
`emit_stashed_diagnostics` itself to avoid an abort in
`DiagCtxtInner::drop` when stashed diagnostics occur.

Fixes #121450.

1 files changed, 3 insertions, 0 deletions

diff --git a/src/tools/rustfmt/tests/parser/stashed-diag.rs b/src/tools/rustfmt/tests/parser/stashed-diag.rs
new file mode 100644
index 00000000000..3b0b543e610
--- /dev/null
+++ b/src/tools/rustfmt/tests/parser/stashed-diag.rs
@@ -0,0 +1,3 @@
+#![u={static N;}]
+
+fn main() {}