nir,radv,aco,ac/llvm: add and use nir_op_fmulz and nir_op_ffmaz
Optimizes the multiplication pattern ((b==0.0 ? 0.0 : a) * (a==0.0 ? 0.0 : b)
) created by https://github.com/doitsujin/dxvk/pull/2294
Based on !13434 (merged)
Optimizes the multiplication pattern ((b==0.0 ? 0.0 : a) * (a==0.0 ? 0.0 : b)
) created by https://github.com/doitsujin/dxvk/pull/2294
Based on !13434 (merged)