Simplify data handling

src/format.cc

@@ -55,10 +55,6 @@ vformat_to(buffer<char>&, string_view,
                type_identity_t<char>>>);
 }  // namespace detail
 
-// Clang doesn't allow dllexport on template instantiation definitions:
-// https://reviews.llvm.org/D61118.
-template struct FMT_INSTANTIATION_DEF_API detail::basic_data<void>;
-
 // Workaround a bug in MSVC2013 that prevents instantiation of format_float.
 int (*instantiate_format_float)(double, int, detail::float_specs,
                                 detail::buffer<char>&) = detail::format_float;