feat(asm): encode the arm64 local-exec TLS load

Assisted-by: GLM 5.3 Flash

asm/elfarm64.go

@@ -18,6 +18,9 @@ const (
 	rArm64AddAbsLo12NC = 277 // R_AARCH64_ADD_ABS_LO12_NC (ADD page offset)
 	rArm64Call26       = 283 // R_AARCH64_CALL26 (BL instruction)
 	rArm64Ldst64Lo12NC = 286 // R_AARCH64_LDST64_ABS_LO12_NC (64-bit LDR/STR page offset)
+	// R_AARCH64_TLSLE_MOVW_TPREL_G0 (debug/elf 547): the local-exec TLS
+	// load's MOVZ field, the module offset at bits [15:0].
+	rArm64TLSLEMovwTprelG0 = 547
 	// R_AARCH64_ABS32 (debug/elf 258): the absolute 32-bit address of a
 	// symbol, the R_ADDR shape a 4-byte DATA field carries.  ABS64 (257)
 	// lives with the DWARF fixup constants as rAARCH64Abs64.
@@ -131,6 +134,11 @@ func (img *Image) ELFAARCH64Object() ([]byte, error) {
 					elfRela{off: uint64(fn.Offset + r.Off), typ: rArm64PrelPgHi21, sym: idx, addend: r.Addend},
 					elfRela{off: uint64(fn.Offset + r.Off + 4), typ: rArm64Ldst64Lo12NC, sym: idx, addend: r.Addend},
 				)
+			case RelArm64TLSLE:
+				// The local-exec MOVZ: one relocation over the imm16 field.
+				relas = append(relas, elfRela{
+					off: uint64(fn.Offset + r.Off), typ: rArm64TLSLEMovwTprelG0, sym: idx, addend: r.Addend,
+				})
 			default:
 				return nil, fmt.Errorf("relocation kind %v unsupported in ELF emission", r.Kind)
 			}