2a025c1a76
This wasn't necessary for msvc and caused issues where different types with the same name such as different instantiations of `Option<T>` would have colliding debuginfo. This confused the debugger which would pick one of the type definitions and use for all types with that name even though they had different layout.
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.