[clang] [llvm] [mlir] Enforce single-operand form for llvm.loop.vectorize.predicate metadata (PR #213902)

[Michael Kruse via llvm-commits]

================
@@ -7082,18 +7091,9 @@ static Metadata *upgradeLoopArgument(Metadata *MD) {
 
   LLVMContext &C = T->getContext();
 
-  // Rewrite the old two-operand distribute form to the single-operand pair.
-  if (isOldDistributeEnable(T)) {
-    bool Enable = !mdconst::extract<ConstantInt>(T->getOperand(1))->isZero();
-    return MDTuple::get(
-        C, {MDString::get(C, Enable ? "llvm.loop.distribute.enable"
-                                    : "llvm.loop.distribute.disable")});
-  }
-
-  // Rewrite the modern two-operand vectorize.enable form to the single-operand
-  // enable/disable pair.
-  if (isOldVectorizeEnable(T))
-    return makeVectorizeEnableNode(C, T->getOperand(1));
+  // Rewrite a removed two-operand boolean form to the single-operand pair.
----------------
Meinersbur wrote:

```suggestion
  /// Rewrite a removed two-operand boolean form to the single-operand pair.
```
[nit]

https://github.com/llvm/llvm-project/pull/213902