[PATCH x86_64] Update memcpy, mempcpy and memmove selection order for Excavator CPU BZ #19583

[Pawar, Amit]

>A few comments:
>
>1. Since there is bit_arch_Fast_Copy_Backward already, please add bit_arch_Avoid_AVX_Fast_Unaligned_Load instead.
Thought to ask for one more suggestion, bit_arch_Avoid_AVX_Fast_Unaligned_Load is more readable but what to select by avoiding it? Can it be used to set any feature bit and not only Fast_Copy_Backward right? 

>2. Please verify that index_arch_XXX are the same and use one index_arch_XXX to set all bits.  There are examples in sysdeps/x86/cpu-features.c.
My fault, didn’t notice that.

>3. Please use proper ChangeLog format:
>
>        * file (name of function, macro, ...): What changed.
>

Thanks,
Amit Pawar