[PATCH] Add support for RISC-V Z-extension arch attributes.

[Jim Wilson]

On Mon, Jul 29, 2019 at 6:10 AM Maxim Blinov <maxim.blinov@embecosm.com> wrote:
> +#define RISCV_STD_Z_EXT_COUNT 12
> +extern const char * const z_ext_strtab[RISCV_STD_Z_EXT_COUNT];

I'd suggest defining the constant to a sizeof expression and not
specifying an array bound.  That eliminates a source of error if
someone adds a new z extension and forgets to update the constant.

I think this patch is basically correct.  It just needs some cleanup,
and we need some clarification on how exactly to sort the extensions.

Jim