The only user is unreachable (ignore_runtime is false).

now the frontend is only responsible to mangle the ld_name, entity
creation is left to libfirm which now also caches the entities.

structs are bad in a library API. We provide setter functions for the
fields now.

You should specify the pinned attribute when calling new_ir_op and not
change it later.

Correct and simplify emitting Add/Sub on AMD64 now that should_be_same constraints are resolved with copies.