PR21441, Unnecessary padding of .eh_frame section

PR21441, Unnecessary padding of .eh_frame section

Until all .eh_frame sections have been edited we don't know their
sizes.  So it isn't possible to properly decide whether a non-empty
.eh_frame section follows a given section until editing is complete.

bfd/
	PR 21441
	* elf-eh-frame.c (_bfd_elf_discard_section_eh_frame): Don't add
	alignment padding here.
	* elflink.c (bfd_elf_discard_info): Add .eh_frame padding here
	in a reverse pass over sections.
ld/
	PR 21441
	* testsuite/ld-x86-64/pr21038a.d: Adjust.
	* testsuite/ld-x86-64/pr21038a-now.d: Adjust.