Remove `BorrowckErrors::tainted_by_errors` This PR removes one of the `tainted_by_errors` occurrences, replacing it with direct use of `ErrorGuaranteed`. r? `@oli-obk`
DiagCtxt
EarlyDiagCtxt
String
StringPart
DiagnosticBuilder::into_diagnostic
DiagnosticArgValue::Number
SilentEmitter::fatal_note
_ == _ || _ == _
matches!(_, _ | _)
DiagnosticArg