The test pushed mrb_int via vf.i but the format read int via %!d. On
x86_64/aarch64 the va_arg slots overlap so reading the low 32 bits of
the pushed int64 returned the right value, but on strict-alignment
ABIs (MIPS o32) va_arg(ap, int) reads the alignment padding and the
format prints 0 instead of the value.
Make the format match the helper: vf.i pairs with %!i (reads mrb_int),
matching the surrounding lines 44-50 convention and the "inspect
mrb_int" label.
Reported by vobloeb in #6857.
Co-authored-by: Claude <noreply@anthropic.com>
Yukihiro "Matz" Matsumoto
36dd9eab88