01e6e60bf3
... this is a special attribute that was made to be a target-feature in LLVM 18+, but in all previous versions, this "feature" is a naked attribute. We will have to handle this situation differently than all other target-features.
The codegen crate contains the code to convert from MIR into LLVM IR,
and then from LLVM IR into machine code. In general it contains code
that runs towards the end of the compilation process.
For more information about how codegen works, see the rustc dev guide.