deps: workaround stod() limitations on SmartOS

std::stod() on SmartOS does not currently handle hex strings. This
commit provides a workaround based on strtol() until proper stod()
support is available.

PR-URL: https://github.com/nodejs/node/pull/36139


Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: Shelley Vohr <codebytere@gmail.com>