Rewrite E0019 example
Rewrite E0019 example

Inline assembly is now the only user of E0019. What is it doing that
E0015 is not?

aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust