GlobalISel: remove "unsized" LLT

It was only really there as a sentinel when instructions had to have precisely
one type. Now that registers are typed, each register really has to have a type
that is sized.

llvm-svn: 281599

llvm/lib/CodeGen/MachineVerifier.cpp

@@ -1051,7 +1051,7 @@ MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
           }
 
           // Make sure the register fits into its register bank if any.
-          if (RegBank && Ty.isSized() &&
+          if (RegBank && Ty.isValid() &&
               RegBank->getSize() < Ty.getSizeInBits()) {
             report("Register bank is too small for virtual register", MO,
                    MONum);