e3e342a90b
This was a bit more invasive than I had kind of hoped. An alternate approach would be to add an extra call_intrinsic_with_attrs() that would have the new-in-this-change signature for call_intrinsic, but this felt about equivalent and made it a little easier to audit the relevant callsites of call_intrinsic().
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.