The following patch adds USES+=elfctl and marks the Julia executable as "wxneeded." While here, sort USES.

Here are samples of what happens when kern.elf64.allow_wx=0 and when kern.elf64.allow_wx=1 before the executable is properly tagged:

$ sysctl kern.elf64.allow_wx
kern.elf64.allow_wx: 0
$ julia
fatal: error thrown and no exception handler available.
InitError(mod=:Sys, error=ErrorException("PCRE JIT error: no more memory"))
unknown function (ip: 0x844d5ee08)
unknown function (ip: 0x844da02af)
unknown function (ip: 0x844a7ea39)
unknown function (ip: 0x844d3e8da)
unknown function (ip: 0x844a9a42e)
unknown function (ip: 0x844d59a1d)
unknown function (ip: 0x844d59a78)
ijl_apply_generic at /usr/local/bin/../lib/julia/libjulia-internal.so.1 (unknown line)
ijl_base_relative_to at /usr/local/bin/../lib/julia/libjulia-internal.so.1 (unknown line)
julia_init at /usr/local/bin/../lib/julia/libjulia-internal.so.1 (unknown line)
julia_init at /usr/local/bin/../lib/julia/libjulia-internal.so.1 (unknown line)
jl_repl_entrypoint at /usr/local/bin/../lib/julia/libjulia-internal.so.1 (unknown line)
main at /usr/local/bin/julia (unknown line)
_start at /usr/local/bin/julia (unknown line)
unknown function (ip: 0x821877007)

$ sysctl kern.elf64.allow_wx
kern.elf64.allow_wx: 1
$ julia
               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
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  | | |_| | | | (_| |  |  Version 1.9.4 (2023-11-14)
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julia>