PR20659, Objcopy and change section lma failing

PR20659, Objcopy and change section lma failing

Sections may well belong in multiple segments.  The testcase in the PR
saw an allocated section being assigned to an ABIFLAGS segment, then
not being assigned to a LOAD segment because it had already been
handled.  To fix that particular problem this patch sets and tests
segment_mark only for LOAD segments.  I kept the segment_mark test for
LOAD segments because I think there may otherwise be a problem with
zero size sections.

A few other problems showed up with the testcase.  Some targets align
.dynamic, resulting in the test failing with "section .dynamic lma
0x800000c0 adjusted to 0x800000cc" and similar messages.  I've tried
to handle that with some more hacks to the segment lma, which do the
right thing for the testcase, but may well fail in other situations.

I've also removed the tests of segment lma (p_paddr) and code involved
in deciding that an adjusted segment no longer covers the file or
program headers.  Those test can't be correct in the face of objcopy
--change-section-lma.  It may be necessary to reinstate the tests but
do them modulo page size, but we'll see how this goes.

	PR 20659
bfd/
	* elf.c (rewrite_elf_program_header): Use segment_mark only for
	PT_LOAD headers.  Delete first_matching_lma and first_suggested_lma.
	Instead make matching_lma and suggested_lma pointers to the
	sections.  Align section vma and lma calculated from segment.
	Don't clear includes_phdrs or includes_filehdr based on p_paddr
	test.  Try to handle alignment padding before first section by
	adjusting new segment lma down.  Adjust PT_PHDR map p_paddr.
ld/
	* testsuite/ld-elf/changelma.d,
	* testsuite/ld-elf/changelma.lnk,
	* testsuite/ld-elf/changelma.s: New test.