[Patch, BFD, AArch64] Fix PT_GNU_PROPERTY alignment issue

[Nick Clifton]

Hi Sudi,

> bfd/ChangeLog:
> 2019-xx-xx  Sudakshina Das  <sudi.das@arm.com>
> 
> 	* elfxx-aarch64.c (_bfd_aarch64_elf_link_setup_gnu_properties): Set
> 	alignment of the new gnu property section.
> 
> ld/ChangeLog:
> 2019-xx-xx  Sudakshina Das  <sudi.das@arm.com>
> 
> 	* testsuite/ld-aarch64/aarch64-elf.exp: Add new tests.
> 	* testsuite/ld-aarch64/property-bti-pac4-a.d: New test.
> 	* testsuite/ld-aarch64/property-bti-pac4-b.d: New test.
> 	* testsuite/ld-aarch64/property-bti-pac4.s: New test.

Approved - please apply.

Cheers
  Nick