External symbols are defined via deflabel(), but deflabel() is not
called until pass0 == 1. Until that happens, segbase has no way to
know what the proper segment base of the segment actually is.
Thus, testing for pass0 == 0 will always fail for a forward reference;
correct the test to test for pass0 < 2, i.e. the assert should fail
only for the final code-generation pass.
Reported-by: <stsp@list.ru>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
4885cc2ba8