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

[Justin Bogner via llvm-commits]

================
@@ -287,34 +288,40 @@ PreservedAnalyses RootSignatureAnalysisPrinter::run(Module &M,
     OS << indent(Space) << "Version: " << RS.Version << "\n";
     OS << indent(Space) << "RootParametersOffset: " << RS.RootParameterOffset
        << "\n";
-    OS << indent(Space) << "NumParameters: " << RS.Parameters.size() << "\n";
+    OS << indent(Space) << "NumParameters: " << RS.ParametersContainer.size()
+       << "\n";
     Space++;
-    for (auto const &P : RS.Parameters) {
-      OS << indent(Space) << "- Parameter Type: " << P.Header.ParameterType
-         << "\n";
+    for (size_t I = 0; I < RS.ParametersContainer.size(); I++) {
+      const auto &[Type, Loc] =
+          RS.ParametersContainer.getTypeAndLocForParameter(I);
+      const dxbc::RootParameterHeader Header =
+          RS.ParametersContainer.getHeader(I);
+
+      OS << indent(Space) << "- Parameter Type: " << Type << "\n";
       OS << indent(Space + 2)
-         << "Shader Visibility: " << P.Header.ShaderVisibility << "\n";
-      switch (P.Header.ParameterType) {
-      case llvm::to_underlying(dxbc::RootParameterType::Constants32Bit):
-        OS << indent(Space + 2)
-           << "Register Space: " << P.Constants.RegisterSpace << "\n";
+         << "Shader Visibility: " << Header.ShaderVisibility << "\n";
+
+      switch (Type) {
+      case llvm::to_underlying(dxbc::RootParameterType::Constants32Bit): {
+        auto Constants = RS.ParametersContainer.getConstant(Loc);
----------------
bogner wrote:

Better to spell the type out here (also we should make this a const ref instead of copying it):
```suggestion
        const dxbc::RootConstants &Constants =
            RS.ParametersContainer.getConstant(Loc);
```

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