The main change is in building the libraries, where -fshort-enums was
passed on RISC-V while other C files weren't compiled with this setting.
Note: the test already passed before this change, but it seems like a
good idea to explicitly test for enum size consistency.
There is also not a particular reason not to pass -fshort-enums on
RISC-V. Perhaps it's better to do it there too (on baremetal targets
that don't have to worry about binary compatibility).