New "owner" attribute for gdb.Objfile.

gdb/ChangeLog:

	* NEWS: Mention gdb.Objfile.owner.
	* python/py-objfile.c (objfpy_get_owner): New function.
	(objfile_getset): Add "owner".

gdb/doc/ChangeLog:

	* python.texi (Objfiles In Python): Document Objfile.owner.

gdb/testsuite/ChangeLog:

	* gdb.python/py-objfile.exp: Add tests for objfile.owner.
	* configure.ac: Add od-elf32_avr to build.
	* configure: Regenerate.
	* od-elf32_avr.c: New file.
	* objdump.h: Declare objdump_private_desc_elf32_avr.
	* od-elf32_avr.c: Forgot to add a new file.
More fixes for invalid memory accesses triggered by fuzzed binaries.

	PR binutils/17531
	* dwarf.c (display_debug_frames): Check for a negative
	augmentation data length.
	(display_gdb_index): Check for invalid offsets.
	* elfcomm.c (process_archive_index_and_symbols): Check for an
	index number that overflows when multiplied by the ar index size.
	* readelf.c (dump_ia64_unwind): Add range checks.
	(slurp_ia64_unwind_table): Change to a boolean function.  Add
	range checks.
	(process_version_sections): Add range checks.
	(get_symbol_version_string): Add check for missing section
	headers.
Automatic date update in version.in