tidy: Check that cargo and compiletest share the same rustfix.
tidy: Check that cargo and compiletest share the same rustfix.

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