In this PR we're emitting -Wnoexcept warnings about potentially-throwing NSDMIs
when computing the noexcept specification of a class's defaulted default
constructor. Although these warnings are in some sense valid, this patch takes
the route of suppressing them, because:
1. the warning message is confusing in its current form;
2. warning for 'struct C { B b = B(); };' but not for 'struct C { B b; };'
is inconsistent; and
3. emitting a warning here arguably doesn't fall under the umbrella of
-Wnoexcept, whose documentation says it warns only when a
noexcept-expression evaluates to false, but there are no
noexcept-expressions here.
gcc/cp/ChangeLog:
PR c++/93805
* except.c (maybe_noexcept_warning): Add TODO comment.
* method.c (walk_field_subobs): Pass tf_none to expr_noexcept_p.
gcc/testsuite/ChangeLog:
PR c++/93805
* g++.dg/warn/Wnoexcept2.C: New test.
