[llvm] [CodeGen][NFC] Add laneBitmask as new MachineOperand Type (PR #151944)

[Matt Arsenault via llvm-commits]

================
@@ -288,6 +288,23 @@ TEST(MachineOperandTest, PrintGlobalAddress) {
   }
 }
 
+TEST(MachineOperandTest, PrintLaneMask) {
+  // Create a MachineOperand with a lanemask and print it.
+  LaneBitmask LaneMask = LaneBitmask(12);
+  MachineOperand MO = MachineOperand::CreateLaneMask(LaneMask);
+
+  // Checking some preconditions on the newly created
+  // MachineOperand.
+  ASSERT_TRUE(MO.isLaneMask());
+  ASSERT_TRUE(MO.getLaneMask() == LaneMask);
----------------
arsenm wrote:

```suggestion
  EXPECT_EQ(MO.getLaneMask(), LaneMask);
```

https://github.com/llvm/llvm-project/pull/151944