[basic.def.odr] A variable is "named by" an expression (#5534)

The previous wording, a variable "whose name appears
as [an] expression", is less precise and not well-defined.

Author: xmh0511

source/basic.tex

@@ -440,7 +440,7 @@
 \label{term.odr.use}%
 A variable is named by an expression
 if the expression is an \grammarterm{id-expression} that denotes it.
-A variable \tcode{x} whose name appears as a
+A variable \tcode{x} that is named by a
 potentially-evaluated expression $E$
 is \defnx{odr-used}{odr-use} by $E$ unless
 \begin{itemize}