image/draw: test crashes on linux/arm64

[mikioh]

https://go.googlesource.com/go/+/33448d963caf0d66f042e738fe733c66796742b2 enables to build on linux/arm64, and so we are able to see this issue.

ok      image   0.488s
ok      image/color 0.055s
?       image/color/palette [no test files]
signal: segmentation fault (core dumped)
FAIL    image/draw  0.395s
ok      image/gif   0.163s
?       image/internal/imageutil    [no test files]
ok      image/jpeg  0.556s
ok      image/png   0.137s

See http://build.golang.org/log/7ceea9275e0c0b5fa62c4971612475023e24f225.

[josharian]

Dup of #10304?

[mikioh]

Yup, thanks.