[clang] [Clang][docs] Modify generator for HLSL semantics documentation (PR #157841)

[Nathan Gauër via cfe-commits]

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@@ -5209,6 +5209,14 @@ class SpellingList {
                              Other.Spellings[Kind].end());
     }
   }
+
+  unsigned getSpellingCount() const {
+    unsigned Count = 0;
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Keenuts wrote:

Still kept a loop as we have a C-array of vectors, so no proper iterators.
Might be able to use llvm's range with raw pointers, but a loop should be fine.
Changed to `hasSpelling` as suggested still 😊 

https://github.com/llvm/llvm-project/pull/157841