Such that we can now have something like: ``` PseudoVFMACC_VV_M2_E64 %1, %28, %28, 7 /* frm=dyn */, %21 /* vl */, 6 /* e64 */, 0 /* tu, mu */ ``` or ``` PseudoVFMACC_VV_M2_E64 %1, %28, %28, 7 /* frm=dyn */, -1 /* vl=VLMAX */, 6 /* e64 */, 0 /* tu, mu */ ``` Hopefully this could make reading RISC-V MIR (a little) less painful.