Predicate lvalue

Holds if e is evaluated just for its location. This includes expressions that are used in a reference expression (&foo), expressions that are used on the left side of an assignment, and some non-expression types such as Initializer.

For expressions, this is similar to, but different than, e.(Expr).isLValue(), which holds if e has an address.

This relation pervasively influences the interpretation of expressions throughout this module. An element evaluated for its lvalue is treated as evaluating to its location, not its value.