[clang] Try to fix builders

Try to fix these errors:

SemaDeclCXX.cpp:16666:19: error: declaration of ‘const clang::Expr* clang::Sema::DiagnoseStaticAssertDetails(const clang::Expr*)::<unnamed struct>::Expr’ changes meaning of ‘Expr’ [-fpermissive]
16666 |       const Expr *Expr;
      |                   ^~~~