Keep unstable target features for asm feature checking Inline assembly uses the target features to determine which registers are available on the current target. However it needs to be able to access unstable target features for this. Fixes #99071
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.