[binutils-gdb] Remove .eh_frame zero terminators

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 9866ffe25a0fe73f5153f2720650baf0dd9cc828 ***

Author: Alan Modra <amodra@gmail.com>
Branch: master
Commit: 9866ffe25a0fe73f5153f2720650baf0dd9cc828

Remove .eh_frame zero terminators

The machinery to do this was there, but not enabled if the terminator
was the only thing in the section.

bfd/
	* elf-eh-frame.c (_bfd_elf_parse_eh_frame): Don't exit early
	for a section containing just a terminator.  Allow multiple
	terminators at end of section.
	* elflink.c (bfd_elf_discard_info): Iterate over .eh_frame
	sections when not adding alignment.  Assert on terminator in
	the middle of FDEs.
ld/
	* testsuite/ld-elf/eh3.d: Update.
	* testsuite/ld-elf/eh4.d: Update.