cmd/cgo: fix cgo with gccgo
cmd/cgo: fix cgo with gccgo

Change-Id: I1780899255e22c16d7f8e9947609a1c284d7c42e
Reviewed-on: https://go-review.googlesource.com/21690
Reviewed-by: David Crawshaw <a2f0bf29257797dd66800b4fbb9945c3e216c004@golang.org>
Run-TryBot: Michael Hudson-Doyle <5e87ffb38a52af6fb9a19b679e9122c7a4d601a5@canonical.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

linux-on-ibm-z/go,goodlang/good,derekmarcotte/go,Cofyc/go,vsekhar/elastic-go,linux-on-ibm-z/go,codestation/go,josharian/go,cloudflare/go,CAFxX/go,nawawi/go,akutz/go,josharian/go,ganboing/go-esx,derekmarcotte/go,momchil-velikov/go,codestation/go,akutz/go,vsekhar/elastic-go,momchil-velikov/go,goodlang/good,CAFxX/go,Cofyc/go,4ad/go,linux-on-ibm-z/go,akutz/go,vanloswang/go,Cofyc/go,codestation/go,polyverse-security/go,4ad/go,goodlang/good,theif519/go,polyverse-security/go,vsekhar/elastic-go,CAFxX/go,derekmarcotte/go,theif519/go,codestation/go,Cofyc/go,CAFxX/go,Cofyc/go,derekmarcotte/go,theif519/go,polyverse-security/go,linux-on-ibm-z/go,vsekhar/elastic-go,derekmarcotte/go,akutz/go,CAFxX/go,derekmarcotte/go,akutz/go,suncycheng/go,josharian/go,nawawi/go,goodlang/good,golang/go,linux-on-ibm-z/go,theif519/go,suncycheng/go,derekmarcotte/go,ganboing/go-esx,ImJasonH/go,suncycheng/go,linux-on-ibm-z/go,codestation/go,momchil-velikov/go,nawawi/go,suncycheng/go,codestation/go,vsekhar/elastic-go,CAFxX/go,akutz/go,christopher-henderson/Go,linux-on-ibm-z/go,4ad/go,josharian/go,nawawi/go,ganboing/go-esx,theif519/go,ganboing/go-esx,ganboing/go-esx,theif519/go,codestation/go,suncycheng/go,momchil-velikov/go,golang/go,ImJasonH/go,vanloswang/go,theif519/go,josharian/go,linux-on-ibm-z/go,polyverse-security/go,vanloswang/go,ImJasonH/go,Cofyc/go,ganboing/go-esx,golang/go,josharian/go,akutz/go,momchil-velikov/go,cloudflare/go,goodlang/good,vsekhar/elastic-go,momchil-velikov/go,polyverse-security/go,polyverse-security/go,vsekhar/elastic-go,polyverse-security/go,vanloswang/go,golang/go,cloudflare/go,ImJasonH/go,polyverse-security/go,goodlang/good,josharian/go,nawawi/go,vanloswang/go,derekmarcotte/go,4ad/go,Cofyc/go,vanloswang/go,suncycheng/go,Cofyc/go,cloudflare/go,ImJasonH/go,vsekhar/elastic-go,goodlang/good,4ad/go,cloudflare/go,ganboing/go-esx,golang/go,ganboing/go-esx,nawawi/go,goodlang/good,ImJasonH/go,CAFxX/go,nawawi/go,golang/go,vanloswang/go,akutz/go,vanloswang/go,codestation/go,suncycheng/go,cloudflare/go,ImJasonH/go,golang/go,ImJasonH/go,4ad/go,cloudflare/go,josharian/go,4ad/go,suncycheng/go,golang/go,theif519/go,cloudflare/go,nawawi/go,CAFxX/go,momchil-velikov/go,momchil-velikov/go,4ad/go