gcc/

	* config/aarch64/aarch64-option-extensions.def: Add
	AARCH64_OPT_EXTENSION of 'crc'.
	* config/aarch64/aarch64.h (AARCH64_FL_CRC): New define.
	(AARCH64_ISA_CRC): Ditto.
	* doc/invoke.texi (-march and -mcpu feature modifiers): Add
	description of the CRC extension.

From-SVN: r202275