Implements [class.copy]/33 of coroutines TS
When the criteria for elision of a copy/move operation are met, but not
for an exception-declaration, and the object to be copied is designated by an lvalue, or when the
expression in a return or co_return statement is a (possibly parenthesized) id-expression that
names an object with automatic storage duration declared in the body or
parameter-declaration-clause of the innermost enclosing function or lambda-expression, overload resolution to select
the constructor for the copy or the return_value overload to call is first performed as if the object
were designated by an rvalue.