Check that the compiler reports an error for `posedge`, `negedge` and `edge`
event controls on named events. Edge controls can not be used with named
events.
There is already an existing test that checks both `posedge` and `negedge`.
Split it into separate tests so that each invalid event control is checked
independently.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Lars-Peter Clausen