[clang] [NFC][Clang][AST] Adopt simplified `getTrailingObjects` in AST (PR #144432)

[Rahul Joshi via cfe-commits]

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@@ -388,9 +387,7 @@ template <class T> class OMPDirectiveListClause : public OMPClause {
     assert(
         DK.size() == NumKinds &&
         "Number of directive kinds is not the same as the preallocated buffer");
-    std::copy(DK.begin(), DK.end(),
-              static_cast<T *>(this)
-                  ->template getTrailingObjects<OpenMPDirectiveKind>());
+    std::copy(DK.begin(), DK.end(), getDirectiveKinds().begin());
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jurahul wrote:

Thanks, yeah some of these might have sneaked in but I'll do the rest in a follow on

https://github.com/llvm/llvm-project/pull/144432