[ping] allow target (OS) SUBTARGET_OVERRIDE_OPTIONS on aarch64

[Olivier Hainque <hainque at adacore dot com>]

Ping for one of the changes last proposed here:

 https://gcc.gnu.org/ml/gcc-patches/2018-11/msg00761.html

Submitted separately as an attempt to facilitate the review
process.

This one proposes the possibility for target (OS) configurations
to provide a SUBTARGET_OVERRIDE_OPTIONS macro as other CPU ports
do, needed by our aarch64-vxworks7 port to come.

Got access to a linux box, so in addition to the Ada nighty
testing we do on the cross port, bootstrapped and regression
tested on aarch64-linux.

OK to commit ?

Thanks in advance,

With Kind Regards,

Olivier


2018-12-12  Olivier Hainque  <hainque@adacore.com>

	* config/aarch64/aarch64.c (aarch64_override_options): Once arch,
	cpu and tune were validated, insert SUBTARGET_OVERRIDE_OPTIONS if
	defined.

Attachment: 0002-Add-support-for-SUBTARGET_OVERRIDE_OPTIONS-on-aarch6.patch
Description: Binary data