[clang] [llvm] [NFC][HLSL][DirectX] Let `HLSLRootSignature` reuse the `dxbc` defined enums (PR #145986)

[Sarah Spall via llvm-commits]

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@@ -205,20 +205,22 @@ TEST_F(ParseHLSLRootSignatureTest, ValidParseDTClausesTest) {
   ASSERT_EQ(std::get<DescriptorTableClause>(Elem).Space, 0u);
   ASSERT_EQ(std::get<DescriptorTableClause>(Elem).Offset,
             DescriptorTableOffsetAppend);
+  auto ValidDescriptorRangeFlags = llvm::dxbc::DescriptorRangeFlags(0x1000f);
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spall wrote:

that hex value corresponds to validflags?

https://github.com/llvm/llvm-project/pull/145986