cmd/cgo: allow C.malloc(0) always

Because we can, and because it otherwise might crash
the program if we think we're out of memory.

Fixes issue 6390.

R=golang-dev, iant, minux.ma
CC=golang-dev
https://codereview.appspot.com/13345048

1 files changed, 1 insertions, 0 deletions

diff --git a/misc/cgo/test/cgo_test.go b/misc/cgo/test/cgo_test.go
index e36f93597..38151abca 100644
--- a/misc/cgo/test/cgo_test.go
+++ b/misc/cgo/test/cgo_test.go
@@ -46,5 +46,6 @@ func Test3250(t *testing.T)                { test3250(t) }
 func TestCallbackStack(t *testing.T)       { testCallbackStack(t) }
 func TestFpVar(t *testing.T)               { testFpVar(t) }
 func Test4339(t *testing.T)                { test4339(t) }
+func Test6390(t *testing.T)                { test6390(t) }
 
 func BenchmarkCgoCall(b *testing.B) { benchCgoCall(b) }