This is part of the series started by D68484.
The noalias_sidechannel tracks dependencies on noalias intrinsics without
blocking optimizations on the pointer value.
Note: this implementation might have some speed effect on all instruction
because of the extra bit that is used to track if the noalias_sidechannel is
present or not. This might impact the computation of the number of arguments.
Note: this is a stable point and tests should run fine with the patches applied up to this point.