[clang] [llvm] [HLSL][RootSignature] Add parsing for empty RootConstants (PR #137999)

[Finn Plummer via cfe-commits]

================
@@ -252,6 +252,32 @@ TEST_F(ParseHLSLRootSignatureTest, ValidSamplerFlagsTest) {
   ASSERT_TRUE(Consumer->isSatisfied());
 }
 
+TEST_F(ParseHLSLRootSignatureTest, ValidParseRootConsantsTest) {
----------------
inbelic wrote:

Once we add the mandatory parameters then having an empty `RootConstants` is no longer valid, so the idea is that we can merge them into one

https://github.com/llvm/llvm-project/pull/137999