meta: make meta_ctx_arg_t available via fwd.hpp as it should be

src/entt/meta/context.hpp

@@ -26,12 +26,6 @@ struct meta_context {
 } // namespace internal
 /*! @endcond */
 
-/*! @brief Disambiguation tag for constructors and the like. */
-class meta_ctx_arg_t final {};
-
-/*! @brief Constant of type meta_context_arg_t used to disambiguate calls. */
-inline constexpr meta_ctx_arg_t meta_ctx_arg{};
-
 /*! @brief Opaque meta context type. */
 class meta_ctx: private internal::meta_context {
     // attorney idiom like model to access the base class

src/entt/meta/fwd.hpp

@@ -32,6 +32,12 @@ class meta_factory;
 /*! @brief Used to identicate that a sequence container has not a fixed size. */
 inline constexpr stl::size_t meta_dynamic_extent = (stl::numeric_limits<stl::size_t>::max)();
 
+/*! @brief Disambiguation tag for constructors and the like. */
+class meta_ctx_arg_t final {};
+
+/*! @brief Constant of type meta_context_arg_t used to disambiguate calls. */
+inline constexpr meta_ctx_arg_t meta_ctx_arg{};
+
 } // namespace entt
 
 #endif