ASM static binary -> dynamic loading without linking with ld

This directory contains the same 42.asm as 0_static, with an added call to __printf and argument "hello world" that will be replaced by puts from glibc.

rewrite.go takes a.out as input and outputs dyn with changed elf headers so that:

1. interp is added so we get loaded dynamically
2. libc.so.6 is added as needed library
3. contents of __printf in .bss get changed to point to puts from libc.so.6
4. profit: ./dyn outputs hello world, is statically compiled (without libc!), but can call into the dynamic symbol puts