Include diagnostics regression

ref rust-lang/rust#119273

Author: jhpratt

tests/compile-fail/invalid_serializer.stderr

@@ -79,3 +79,35 @@ error[E0432]: unresolved import `not_string`
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no external crate `not_string`
    |
    = note: this error originates in the macro `serde::format_description` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0391]: cycle detected when computing type of opaque `my_format::description::{opaque#0}`
+  --> ../tests/compile-fail/invalid_serializer.rs:14:1
+   |
+14 | serde::format_description!(my_format, OffsetDateTime, not_string); // string format wrong type
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: ...which requires borrow-checking `my_format::description`...
+  --> ../tests/compile-fail/invalid_serializer.rs:14:1
+   |
+14 | serde::format_description!(my_format, OffsetDateTime, not_string); // string format wrong type
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+note: ...which requires promoting constants in MIR for `my_format::description`...
+  --> ../tests/compile-fail/invalid_serializer.rs:14:1
+   |
+14 | serde::format_description!(my_format, OffsetDateTime, not_string); // string format wrong type
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+note: ...which requires const checking `my_format::description`...
+  --> ../tests/compile-fail/invalid_serializer.rs:14:1
+   |
+14 | serde::format_description!(my_format, OffsetDateTime, not_string); // string format wrong type
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: ...which requires computing whether `my_format::description::{opaque#0}` is freeze...
+   = note: ...which requires evaluating trait selection obligation `my_format::description::{opaque#0}: core::marker::Freeze`...
+   = note: ...which again requires computing type of opaque `my_format::description::{opaque#0}`, completing the cycle
+note: cycle used when computing type of `my_format::description::{opaque#0}`
+  --> ../tests/compile-fail/invalid_serializer.rs:14:1
+   |
+14 | serde::format_description!(my_format, OffsetDateTime, not_string); // string format wrong type
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
+   = note: this error originates in the macro `serde::format_description` (in Nightly builds, run with -Z macro-backtrace for more info)