872631d0f0
Use `as_deref` in compiler (but only where it makes sense) This simplifies some code :3 (there are some changes that are not exacly `as_deref`, but more like "clever `Option`/`Result` method use")
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.