Add option to show what values are tested
Add option to show what values are tested

This is useful to inspect what the script does manually, in particular
to check that expected values do get tested. --keep-c provides the
same information but in a way that's harder to access.

NXPmicro/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls,Mbed-TLS/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,NXPmicro/mbedtls,Mbed-TLS/mbedtls,NXPmicro/mbedtls,ARMmbed/mbedtls,ARMmbed/mbedtls,NXPmicro/mbedtls