[golang-dev] linux-arm-luitvd broken by cmd/ld: fix "_image_base__ not defined" problem for cmd/8l.

Change 46b68d2aa38e broke the linux-arm-luitvd build:
http://build.golang.org/log/6d571a4681355c9bbe7cba59fc931c7c5ad4b6f6

cmd/ld: fix "_image_base__ not defined" problem for cmd/8l.
Fixes issue 6431.

Change suggested by kin.wilson.za.

R=golang-dev, rsc
CC=golang-dev
https://codereview.appspot.com/13314048

http://code.google.com/p/go/source/detail?r=46b68d2aa38e

$ tail -200 < log
net/rpc/jsonrpc
net/smtp
os/user
runtime/debug
runtime/race
testing
testing/iotest
testing/quick
text/scanner

# Testing packages.
? cmd/cgo [no test files]
ok cmd/fix 0.504s
ok cmd/go 0.229s
ok cmd/gofmt 1.398s
? cmd/yacc [no test files]
ok archive/tar 0.143s
ok archive/zip 18.405s
ok bufio 3.266s
ok bytes 4.058s
ok compress/bzip2 1.626s
ok compress/flate 18.734s
ok compress/gzip 0.209s
ok compress/lzw 2.333s
ok compress/zlib 44.314s
ok container/heap 0.060s
ok container/list 0.055s
ok container/ring 0.343s
? crypto [no test files]
ok crypto/aes 0.381s
ok crypto/cipher 0.087s
ok crypto/des 0.396s
ok crypto/dsa 0.231s
ok crypto/ecdsa 0.841s
ok crypto/elliptic 1.547s
ok crypto/hmac 0.086s
ok crypto/md5 0.101s
ok crypto/rand 0.457s
ok crypto/rc4 1.511s
ok crypto/rsa 8.302s
ok crypto/sha1 0.075s
ok crypto/sha256 0.105s
ok crypto/sha512 0.131s
ok crypto/subtle 0.216s
ok crypto/tls 72.178s
ok crypto/x509 27.108s
? crypto/x509/pkix [no test files]
ok database/sql 0.944s
ok database/sql/driver 0.055s
ok debug/dwarf 0.131s
ok debug/elf 0.294s
ok debug/gosym 0.054s
ok debug/macho 0.085s
ok debug/pe 0.177s
? encoding [no test files]
ok encoding/ascii85 0.070s
ok encoding/asn1 0.100s
ok encoding/base32 0.080s
ok encoding/base64 0.091s
ok encoding/binary 0.076s
ok encoding/csv 0.077s
ok encoding/gob 0.750s
ok encoding/hex 0.061s
ok encoding/json 4.217s
ok encoding/pem 0.069s
ok encoding/xml 0.366s
ok errors 0.056s
ok expvar 0.117s
ok flag 0.074s
ok fmt 1.109s
ok go/ast 0.111s
ok go/build 3.326s
ok go/doc 1.792s
ok go/format 0.240s
ok go/parser 1.185s
ok go/printer 13.584s
ok go/scanner 0.100s
ok go/token 1.276s
? hash [no test files]
ok hash/adler32 0.249s
ok hash/crc32 0.059s
ok hash/crc64 0.046s
ok hash/fnv 0.064s
ok html 0.085s
ok html/template 1.453s
ok image 2.152s
ok image/color 0.171s
? image/color/palette [no test files]
ok image/draw 2.044s
ok image/gif 1.605s
ok image/jpeg 4.706s
ok image/png 0.860s
ok index/suffixarray 0.230s
ok io 0.090s
ok io/ioutil 0.069s
ok log 0.110s
ok log/syslog 2.681s
ok math 0.109s
ok math/big 11.976s
ok math/cmplx 0.071s
ok math/rand 0.665s
ok mime 0.073s
ok mime/multipart 11.928s
ok net 9.132s
ok net/http 42.416s
ok net/http/cgi 6.913s
ok net/http/cookiejar 0.231s
ok net/http/fcgi 0.160s
ok net/http/httptest 0.178s
ok net/http/httputil 0.355s
? net/http/pprof [no test files]
ok net/mail 0.133s
ok net/rpc 0.403s
ok net/rpc/jsonrpc 0.220s
ok net/smtp 0.172s
ok net/textproto 0.149s
ok net/url 0.103s
ok os 7.668s
ok os/exec 5.552s
ok os/signal 0.670s
ok os/user 0.072s
ok path 0.063s
ok path/filepath 0.978s
ok reflect 1.980s
ok regexp 2.825s
ok regexp/syntax 14.946s
ok runtime 190.099s
? runtime/cgo [no test files]
ok runtime/debug 0.084s
ok runtime/pprof 48.839s
? runtime/race [no test files]
ok sort 2.231s
ok strconv 10.597s
ok strings 3.617s
ok sync 1.333s
ok sync/atomic 0.651s
ok syscall 0.259s
ok testing 0.046s
? testing/iotest [no test files]
ok testing/quick 1.383s
ok text/scanner 0.120s
ok text/tabwriter 0.113s
ok text/template 0.760s
ok text/template/parse 0.229s
ok time 13.824s
ok unicode 0.036s
ok unicode/utf16 0.061s
ok unicode/utf8 0.126s
? unsafe [no test files]

real 46m7.034s
user 20m58.250s
sys 1m42.640s

# GOMAXPROCS=2 runtime -cpu=1,2,4
ok runtime 585.140s

# sync -cpu=10
ok sync 1.782s

# ../misc/cgo/stdio

# ../misc/cgo/life

# ../misc/cgo/test
PASS
ok _/tmp/gobuilder/linux-arm-luitvd-46b68d2aa38e/go/misc/cgo/test 5.301s
PASS
ok _/tmp/gobuilder/linux-arm-luitvd-46b68d2aa38e/go/misc/cgo/test 5.217s
PASS
ok _/tmp/gobuilder/linux-arm-luitvd-46b68d2aa38e/go/misc/cgo/test 5.216s
ok _/tmp/gobuilder/linux-arm-luitvd-46b68d2aa38e/go/misc/cgo/testtls
0.067s
ok _/tmp/gobuilder/linux-arm-luitvd-46b68d2aa38e/go/misc/cgo/testtls
0.066s

# ../misc/cgo/testcdefs

# ../misc/cgo/testso

# ../misc/cgo/errors

# ../doc/progs

real 5m9.481s
user 2m16.530s
sys 0m16.060s

# ../doc/codewalk

real 1m2.812s
user 0m29.170s
sys 0m1.910s

# ../misc/goplay

# ../test/bench/go1
ok _/tmp/gobuilder/linux-arm-luitvd-46b68d2aa38e/go/test/bench/go1 56.812s

# ../test
Build complete, duration 2h30m0.07532457s. Result: error: timed out after
2h30m0s