Determine elf proc stack size by inspecting binary

[mullr]

We currently hardwire elf procs to have a 64k stack. We have the opportunity to find out their actual required stack size, using the keep-stack-sizes compiler directive (perhaps aided by https://crates.io/crates/stack-sizes) and some kind of call graph analysis, to figure out the maximum possible stack size. (This will break on recursive code, which is actually desirable. We at least want an explicit opt-out for that.)

[mullr]

See also https://crates.io/crates/cargo-call-stack