[arm] Add support for Arm Ares

[arm] Add support for Arm Ares

This adds support for the Arm Ares CPU for in the arm port.
It implements the Armv8.2-A architecture with the optional features
of statistical profiling, dot product and FP16 on by default.

Note: Ares is a codename to enable early adopters and in time
we will add the final product name once it's announced.

	* config/arm/arm-cpus.in (ares): New entry.
	* config/arm/arm-tables.opt: Regenerate.
	* config/arm/arm-tune.md: Likewise.
	* doc/invoke.texi (ARM Options): Document ares.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@265881 138bc75d-0d04-0410-961f-82ee72b054a4