[llvm] [NFC] Refactoring MCDXBC to support out of order storage of root parameters (PR #137284)

[Justin Bogner via llvm-commits]

================
@@ -76,29 +77,34 @@ void RootSignatureDesc::write(raw_ostream &OS) const {
   }
 
   assert(NumParameters == ParamsOffsets.size());
-  for (size_t I = 0; I < NumParameters; ++I) {
+  const RootParameterInfo *H = ParametersContainer.begin();
----------------
bogner wrote:

`H` isn't used any more (it's merely incremented)

https://github.com/llvm/llvm-project/pull/137284