Rename meta::has_ellipsis_parameter to meta::is_vararg_function

Abstract

This paper proposes wording to resolve the NB comment FR-017-155.

See also CWG 3112.

Wording

In [meta.syn], rename the function:

consteval bool is_function_parameter(info r);
consteval bool is_explicit_object_parameter(info r);
consteval bool has_default_argument(info r);
consteval bool has_ellipsis_parameteris_vararg_function(info r);

Before [meta.reflection.queries]/42, rename the function and change the descrption in [meta.reflection.queries]/42:

consteval bool has_ellipsis_parameteris_vararg_function(info r);
Returns: true if r represents a function or function type that has an ellipsis in its parameter-type-list (9.3.4.6)is a vararg function (dcl.fct]/4).
Otherwise, false.