[expr.mptr.oper] Rephrase wording for symmetry with P0704R1.

Author: zygoloid

source/expressions.tex

@@ -4008,7 +4008,9 @@
 unless its \grammarterm{cv-qualifier-seq} is \tcode{const}.
 In a \tcode{.*}
 expression whose object expression is an lvalue, the program is ill-formed if the second
-operand is a pointer to member function with \grammarterm{ref-qualifier} \tcode{\&\&}.
+operand is
+a pointer to member function
+whose \grammarterm{ref-qualifier} is \tcode{\&\&}.
 The result of a \tcode{.*} expression
 whose second operand is a pointer to a data member is an lvalue if the first
 operand is an lvalue and an xvalue otherwise. The result of a \tcode{.*} expression whose