[clang-tools-extra] [clang] remove ClassScopeFunctionSpecializationDecl (PR #66636)

[Erich Keane via cfe-commits]

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@@ -2613,70 +2579,6 @@ class TypeAliasTemplateDecl : public RedeclarableTemplateDecl {
   static bool classofKind(Kind K) { return K == TypeAliasTemplate; }
 };
 
-/// Declaration of a function specialization at template class scope.
-///
-/// For example:
-/// \code
-/// template <class T>
-/// class A {
-///    template <class U> void foo(U a) { }
-///    template<> void foo(int a) { }
-/// }
-/// \endcode
-///
-/// "template<> foo(int a)" will be saved in Specialization as a normal
-/// CXXMethodDecl. Then during an instantiation of class A, it will be
-/// transformed into an actual function specialization.
-///
-/// FIXME: This is redundant; we could store the same information directly on
-/// the CXXMethodDecl as a DependentFunctionTemplateSpecializationInfo.
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erichkeane wrote:

I see this fixme here as perhaps some of the 'why'?  

https://github.com/llvm/llvm-project/pull/66636