Add some of the AArch64 relocations seen in the wild.

[emaste]

LGTM

[andrew]

Closed by commit rS275903 (authored by @andrew).

head/sys/sys/elf_common.h

 #define R_386_TLS_LDO_32        32      /* 32 bit offset from start of TLS block */
 #define R_386_TLS_IE_32         33      /* 32 bit offset to GOT static TLS offset entry */
 #define R_386_TLS_LE_32         34      /* 32 bit offset within static TLS block */
 #define R_386_TLS_DTPMOD32      35      /* GOT entry containing TLS index */
 #define R_386_TLS_DTPOFF32      36      /* GOT entry containing TLS offset */
 #define R_386_TLS_TPOFF32       37      /* GOT entry of -ve static TLS offset */
 #define R_386_IRELATIVE         42      /* PLT entry resolved indirectly at runtime */
 
+#define R_AARCH64_ABS64         257     /* Absolute offset */
+#define R_AARCH64_ABS32         258     /* Absolute, 32-bit overflow check */
+#define R_AARCH64_ABS16         259     /* Absolute, 16-bit overflow check */
+#define R_AARCH64_PREL64        260     /* PC relative */
+#define R_AARCH64_PREL32        261     /* PC relative, 32-bit overflow check */
+#define R_AARCH64_PREL16        262     /* PC relative, 16-bit overflow check */
+#define R_AARCH64_COPY          1024    /* Copy data from shared object */
+#define R_AARCH64_GLOB_DAT      1025    /* Set GOT entry to data address */
+#define R_AARCH64_JUMP_SLOT     1026    /* Set GOT entry to code address */
+#define R_AARCH64_RELATIVE      1027    /* Add load address of shared object */
+#define R_AARCH64_TLSDESC       1031    /* Identify the TLS descriptor */
+
 #define R_ARM_NONE              0       /* No relocation. */
 #define R_ARM_PC24              1
 #define R_ARM_ABS32             2
 #define R_ARM_REL32             3
 #define R_ARM_PC13              4
 #define R_ARM_ABS16             5
 #define R_ARM_ABS12             6
 #define R_ARM_THM_ABS5          7