[clang] [HLSL] Rewrite semantics parsing (PR #152537)

[Nathan Gauër via cfe-commits]

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@@ -393,6 +393,14 @@ def warn_hlsl_langstd_minimal :
           "recommend using %1 instead">,
   InGroup<HLSLDXCCompat>;
 
+def err_hlsl_semantic_index_overlap : Error<"semantic index overlap %0">;
+
+def err_hlsl_semantic_missing : Error<"semantic annotations must be present "
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Keenuts wrote:

Added a test for the missing semantic, and removed the 2 others which should be added in a later PR.

https://github.com/llvm/llvm-project/pull/152537