[dcl.list.init] Make spacing around & declarator operator locally consistent. (#3353)

Fixes NB JP 057 (C++20 CD)

Author: jensmaurer

source/declarations.tex

@@ -5680,7 +5680,7 @@
 
 struct A { } a;
 struct B { explicit B(const A&); };
-const B &b2{a};                     // error: cannot copy-list-initialize \tcode{B} temporary from \tcode{A}
+const B& b2{a};                     // error: cannot copy-list-initialize \tcode{B} temporary from \tcode{A}
 \end{codeblock}
 \end{example}