Added some support for Irix 4 shared libraries.

	Added some support for Irix 4 shared libraries.
	* ecoff.c (ecoff_new_section_hook): Set SEC_SHARED_LIBRARY for a
	.lib section.
	(ecoff_sec_to_styp_flags): Set SEC_SHARED_LIBRARY if
	STYP_ECOFF_LIB bit is set.
	(ecoff_compute_section_file_positions): Round the contents of a
	.lib section up to the next page boundary.
	(ecoff_set_section_contents): If we see a .lib section, increment
	the vma by one to count the number of shared libraries we have.
	(ecoff_write_object_contents): Don't crash if we see a
	STYP_ECOFF_LIB section, and don't adjust text_start or data_start
	or bss_size either.