Verilog: separate ID for explicit typecast expressions

[kroening]

This is to avoid any confusion with automatically generated, implicit typecasts.

[tautschnig]

This is failing CI checks. Might be worth adding -p to the test.pl invocation so that we can actually see in more detail what is going wrong. (The changes seem sane, but presumably we elsewhere introduce an ID_typecast expression that is now no longer type checked.)

[kroening]

The changes seem sane, but presumably we elsewhere introduce an ID_typecast expression that is now no longer type checked.

Yes, now fixed.