Replace with portable version in C
Replace with portable version in C

Build a minimal version in C instead of assembly so it easily can be
ported to other archs.

This statically linked C version builds a binary that is 1472 bytes.

fixes #7

docker-library/hello-world,docker-library/hello-world,infosiftr/hello-world,Posytron/teste,infosiftr/hello-world,Posytron/teste