[AArch64] Enable CRC feature in GAS for cortex-a53 and cortex-a57.

Conflicts:
	gas/config/tc-aarch64.c
Correct x86 assembler manual

	* config/tc-i386.c (cpu_arch): Re-arrange avx512* and xsave*
	items.

	* doc/c-i386.texi: Re-arrange avx512* and xsave*.  Add
	clflushopt and se1.  Remove duplicated entries.