News entry for ARC

[Claudiu Zissulescu]

Hi Gerald,

I would like to add the following entry to GCC7.x release notes:

ARC
	* Add support for ARC HS and ARC EM processors.
	* Add support for ARC EM variation found in Intel QuarkSE SoCs.
	* Add support for NPS400 ARC700 based cpus.
	* Thread Local Storage is now supported by ARC cpus.
	* Fix errors for ARC600 when using 32x16 multiplier option.
	* Fix PIE for ARC cpus.
	* New cpu templates are supported via multilib.

What will be the advisable way to have it in?

Thank you,
Claudiu