Alignment not supported?

[Florian Weimer]

* David Malcolm:

>> It's also more type-safe and self-documenting.  Although “int”
>> probably isn't exactly the right type here.
>
> "unsigned int" ?

I think the appropriate type used to be “unsigned HOST_WIDE_INT”
inside GCC at one point.  I don't know what the equivalent on the
libgccjit interface is.  If libgccjit does not support
cross-compilation, size_t should be okay.