[llvm] [Draft] Remove to_underlying from root parameter header (PR #154249)

[Justin Bogner via llvm-commits]

================
@@ -275,11 +275,14 @@ void DXContainerWriter::writeParts(raw_ostream &OS) {
 
       for (DXContainerYAML::RootParameterLocationYaml &L :
            P.RootSignature->Parameters.Locations) {
-        dxbc::RTS0::v1::RootParameterHeader Header{L.Header.Type, L.Header.Visibility,
-                                         L.Header.Offset};
 
-        switch (L.Header.Type) {
-        case llvm::to_underlying(dxbc::RootParameterType::Constants32Bit): {
+        mcdxbc::RootParameterHeader Header{
+            static_cast<dxbc::RootParameterType>(L.Header.Type),
+            static_cast<dxbc::ShaderVisibility>(L.Header.Visibility),
+            L.Header.Offset};
----------------
bogner wrote:

This will become moot after the next step (updating the YAML representation), but it would be good to make our assumptions clear here. A couple of asserts should do:
```c++
        assert(dxbc::isValidParameterType(L.Header.Type && "invalid DXContainer YAML");
        assert(dxbc::isValidShaderVisibility(L.Header.Visibility && "invalid DXContainer YAML");
        dxbc::RootParameterType Type(L.Header.Type);
        dxbc::ShaderVisibility Visibility(L.Header.Visibility);
```




https://github.com/llvm/llvm-project/pull/154249