[clang] Mark CWG562 as N/A

[[https://wg21.link/p1787 | P1787]]: CWG562 is resolved by defining lookup as occurring from a program point.
Wording: A single search in a scope S for a name N from a program point P finds all declarations that precede P to which any name that is the same as N ([basic.pre]) is bound in S. ([basic.lookup]/2)

Reviewed By: #clang-language-wg, cor3ntin, shafik

Differential Revision: https://reviews.llvm.org/D147554