eh_frame_hdr generation quirk

[Jan Beulich]

The first thing _bfd_elf_discard_section_eh_frame() does when
encountering an FDE is

	  /* Ensure this FDE uses the last CIE encountered.  */
	  REQUIRE (last_cie);
	  REQUIRE (hdr.id == (unsigned int) (buf - 4 - last_cie));

Can anyone explain why this condition is required? Compiler-generated
objects likely always meet this, but assembler generated sources easily
don't, due to the CIE re-use logic in gas.
Thus, even after working around the problem that ld doesn't make any
attempt to generate honour --eh-frame-hdr if no shared objects are
involved in linking an executable, the generation of the table still fails
when trying this with the Linux kernel.

Thanks for any clarification,
Jan