[PATCH] Arm64: fix build with old glibc

[Nick Clifton]

Hi Jan,

> opcodes/
> 2019-11-11  Jan Beulich  <jbeulich@suse.com>
> 
> 	* aarch64-opc.c (operand_general_constraint_met_p): Replace
> 	"index" local variable by that of the already existing "num".

Approved - please apply.

Cheers
  Nick