Tiny ELF 32/64 with nasm

Sometimes I need to create a tiny ELF with some assembly code, because I'm restricted in size or just don't like the bloated binary produced by gcc and the linker. The classic reference about this is A Whirlwind Tutorial on Creating Really Teensy ELF Executables for Linux. I often use their nasm listing as a template.

I was working with 64bit code the other day and realized there's no 64bit version of it, so here's one.