[PATCH v2] gas: equates of registers

[Hans-Peter Nilsson]

On Tue, 2 May 2023, Jan Beulich wrote:

> There are two problems: symbol_equated_p() doesn't recognize equates of
> registers, and S_CAN_BE_REDEFINED() goes by section rather than by
> expression type. Both together undermine .eqv and .equiv clearly meaning
> to guard the involved symbols against re-definition (both ways).
> 
> To compensate pseudo_set() now using O_symbol and S_CAN_BE_REDEFINED()
> now checking for O_register,
> - for targets creating register symbols through symbol_{new,create}() ->
>   symbol_init() -> S_SET_VALUE() (alpha, arc, dlx, ia64, m68k, mips,
>   mmix, tic4x, tic54x, plus anything using cgen or itbl-ops), have
>   symbol_init() set their expressions to O_register,

(Heads-up for maintainers or asking for approval though being a 
global maintainer?  Anyway...)

Ok for mmix iff the binutils test-suites (ld, gas, binutils) 
shows no regressions for mmix with this patch.

brgds, H-P