aa874c5513
This reverts commit 8c2b57721728233e074db69d93517614de338055, reversing changes made to 9cf18e98f82d85fa41141391d54485b8747da46f.
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.