Due to BPF stack alignment restrictions, LLVM might change the size used
to stored printf arguments in the stack, resulting in alignment issues
when formatting and outputting those arguments. To avoid this issue, we
promote every non-array argument to 64-bits, assuring the size used to
store the argument is the same used to dereference it later when calling
printf.

Fixes: https://github.com/iovisor/bpftrace/issues/47