Filter: make bitwise and, or, xor higher prio than relational expressions

It seems that the usual use-case for bitwise ops are to apply them on
values rather than on the result of equality/inequality. Therefore, move
away from the C operator precedence order, and ensure bitwise and, or,
xor are higher priority than relational expressions (equality and
inequality).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>