Handle both AIX 3.2 and 4.1 bind output.

Handle both AIX 3.2 and 4.1 bind output.

(make_hdr): Handle data_start being non-zero for 4.1.  Padding
sections are omitted in 4.1, but padding bytes can still be
present.  Calculate bias directly from first real section following bss.

(copy_text_and_data): Correct data section starting point for 4.1.

(adjust_lnnoptrs): Adjust line number pointers correctly for both
3.2 and 4.1, based on published IBM documentation.

(unrelocate_symbols): Compute and subtract relocation offsets for
text and data sections.  Handle data_start being non-zero for 4.1.
Skip unnecessary writes.