[PATCH][AArch64] Add separate feature flag for weaker release consistent load insns

[Nick Clifton]

Hi Szabolcs,

> opcodes/
> 2016-12-20  Szabolcs Nagy  <szabolcs.nagy@arm.com>
> 
> 	* aarch64-tbl.h (RCPC, RCPC_INSN): Define.
> 	(aarch64_opcode_table): Use RCPC_INSN.
> 
> include/
> 2016-12-20  Szabolcs Nagy  <szabolcs.nagy@arm.com>
> 
> 	* opcode/aarch64.h (AARCH64_FEATURE_RCPC): Define.
> 	(AARCH64_ARCH_V8_3): Update.
> 
> gas/
> 2016-12-20  Szabolcs Nagy  <szabolcs.nagy@arm.com>
> 
> 	* config/tc-aarch64.c (aarch64_features): Add rcpc.
> 	* doc/c-aarch64.texi (AArch64 Extensions): Document rcpc.
> 	* testsuite/gas/aarch64/ldst-exclusive-armv8_3.d: Rename to ...
> 	* testsuite/gas/aarch64/ldst-rcpc.d: This.
> 	* testsuite/gas/aarch64/ldst-exclusive-armv8_3.s: Rename to ...
> 	* testsuite/gas/aarch64/ldst-rcpc.s: This.
> 	* testsuite/gas/aarch64/ldst-rcpc-armv8_2.d: New test.

Approved - please apply.

Cheers
  Nick