[PATCH] elf: Support DT_RELR relative relocation format [BZ #27924]

[Florian Weimer]

* Fangrui Song via Libc-alpha:

> @@ -887,7 +893,10 @@ typedef struct
>  #define DT_PREINIT_ARRAY 32		/* Array with addresses of preinit fct*/
>  #define DT_PREINIT_ARRAYSZ 33		/* size in bytes of DT_PREINIT_ARRAY */
>  #define DT_SYMTAB_SHNDX	34		/* Address of SYMTAB_SHNDX section */
> -#define	DT_NUM		35		/* Number used */
> +#define DT_RELRSZ	35
> +#define DT_RELR		36
> +#define DT_RELRENT	37
> +#define	DT_NUM		38		/* Number used */
>  #define DT_LOOS		0x6000000d	/* Start of OS-specific */
>  #define DT_HIOS		0x6ffff000	/* End of OS-specific */
>  #define DT_LOPROC	0x70000000	/* Start of processor-specific */

<http://www.sco.com/developers/gabi/latest/ch5.dynamic.html#tag_encodings>
(Figure 5-10: Dynamic Array Tags, d_tag) still ends at 34, and I'm
worried about collisions with these numbers.

Do you know what the official allocation status for the new constants
is?