Add some tests for various cases of named-field use, both ones that
should work and ones that should be diagnosed as errors.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230523120447.728365-7-peter.maydell@linaro.org>
