[binutils-gdb] PR19323 memory allocation greater than 4G

[sergiodj+buildbot at redhat dot com]

*** TEST RESULTS FOR COMMIT c20f6f63eda61348326a861a155716b8d9073307 ***

Author: Alan Modra <amodra@gmail.com>
Branch: master
Commit: c20f6f63eda61348326a861a155716b8d9073307

PR19323 memory allocation greater than 4G

On 32-bit targets, memory requested for program/section headers on a
fuzzed binary can wrap to 0.  A bfd_alloc of zero bytes actually
returns a one byte allocation rather than a NULL pointer.  This then
leads to buffer overflows.

Making this check unconditional triggers an extremely annoying gcc-5
warning.

	PR19323
	* elfcode.h (elf_object_p): Check for ridiculous e_shnum and
	e_phnum values.