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

[Erich Keane via cfe-commits]

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

or perhaps:

```
bool hasSpelling() const {
return Spellings.end() != llvm::find_if(Spellings, [](const auto &I)->bool { return I.size(); });
}
```

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