Update compiler-builtins
Update compiler-builtins

Picks up the removal of the rustbuild feature, which is still used
in our local shim, along with a comment update explaining the usage.

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