[meta.trans.other] Simplify common_type

... by replacing "a type \tcode{U} such that \tcode{is_same_v<U, remove_cvref_t<U>>} is \tcode{true}" with "a non-reference cv-unqualified type \tcode{U}"

Author: CaseyCarter

source/utilities.tex

@@ -17030,8 +17030,8 @@
   \tcode{add_lvalue_reference_t<const remove_reference_t<A>{}>},
 \item \tcode{\placeholdernc{XREF}(A)} denote a unary class template \tcode{T}
   such that \tcode{T<U>} denotes the same type as \tcode{U} with the addition
-  of \tcode{A}'s cv and reference qualifiers, for a type \tcode{U} such
-  that \tcode{is_same_v<U, remove_cvref_t<U>>} is \tcode{true},
+  of \tcode{A}'s cv and reference qualifiers, for a non-reference cv-unqualified
+  type \tcode{U},
 \item \tcode{\placeholdernc{COPYCV}(FROM, TO)} be an alias for type \tcode{TO}
   with the addition of \tcode{FROM}'s top-level cv-qualifiers.
   \begin{example}