[AArch64] Add support for missing CPUs

[AArch64] Add support for missing CPUs

This patch adds '-mcpu' options for following CPUs:
Cortex-A77, Cortex-A76AE, Cortex-A65, Cortex-A65AE, and Cortex-A34.

Related specifications are as following:
https://developer.arm.com/ip-products/processors/cortex-a

Bootstraped/regtested for aarch64-none-linux-gnu.

2019-09-03  Dennis Zhang  <dennis.zhang@arm.com>

	* config/aarch64/aarch64-cores.def (AARCH64_CORE): New entries
	for Cortex-A77, Cortex-A76AE, Cortex-A65, Cortex-A65AE, and
	Cortex-A34.
	* config/aarch64/aarch64-tune.md: Regenerated.
	* doc/invoke.texi: Document the new processors.

From-SVN: r275333