pub fn to_fluent_args<'iter, 'arg: 'iter>( iter: impl Iterator<Item = DiagnosticArg<'iter, 'arg>> ) -> FluentArgs<'arg>
Convert diagnostic arguments (a rustc internal type that exists to implement
FluentArgs which is necessary to perform translation.
Typically performed once for each diagnostic at the start of
emit_diagnostic and then
passed around as a reference thereafter.