The optimizations from commit e558b29b were never incorporated into the
upstream test generator. This does so now.
As far as I can tell, the changes to the Unicode ranges are purely
cosmetic. Some are formatted as 6-digit hex numbers instead of 4-digit.
Others move the low-surrogates range 0xDC00-0xDCFF to the beginning of the
array, but the union of the ranges is still the same.
This code hasn't been touched in a while, so it's probably good to bring
in the newest versions of the dependencies. We can easily tell if there
was any incompatible effect on the output.
The latest version of filenamify requires using ES modules. We also have
to adapt to a breaking change in regexpu-core (see
https://github.com/mathiasbynens/regexpu-core/pull/49).
Also convert the dependencies to devDependencies, since this tool is not
necessary for executing test262.
