[PATCH] gas/symbols: introduce md_resolve_symbol

[Alan Modra]

On Mon, Jul 18, 2022 at 12:46:53PM +0300, Dmitry Selyutin wrote:
> Assuming GMSD is a special operand, marked as O_md1, the code:
> 
>     .set VREG, GMSD
>     .set REG, VREG
>     extsw REG, 2
> 
> ...fails upon attempts to resolve the value of the symbol. This happens
> since machine-dependent values are not handled in the giant op switch.
> We introduce a custom md_resolve_symbol macro; the ports can use this
> macro to customize the behavior when resolve_symbol_value hits O_md
> operand.

Applied to mainline with a small tweak.

-- 
Alan Modra
Australia Development Lab, IBM