test: fix hardcoded `strtoul()` bindings
test: fix hardcoded `strtoul()` bindings

skoky/node-ffi,craigcomstocks/node-ffi,unbornchikken/node-ffi,craigcomstocks/node-ffi,node-ffi/node-ffi,craigcomstocks/node-ffi,skoky/node-ffi,craigcomstocks/node-ffi,Icenium/node-ffi,unbornchikken/node-ffi,node-ffi/node-ffi,unbornchikken/node-ffi,Icenium/node-ffi,node-ffi/node-ffi,unbornchikken/node-ffi,Icenium/node-ffi,skoky/node-ffi,node-ffi/node-ffi,Icenium/node-ffi,skoky/node-ffi