test: add test for gccgo compiler crash
test: add test for gccgo compiler crash

Gccgo crashed compiling a function that returned multiple zero-sized values.

Change-Id: I499112cc310e4a4f649962f4d2bc9fee95dee1b6
Reviewed-on: https://go-review.googlesource.com/38772
Reviewed-by: Than McIntosh <4b2922593166fc595a9b1a408f34f5d3817fe9d2@google.com>
Run-TryBot: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

codestation/go,akutz/go,linux-on-ibm-z/go,linux-on-ibm-z/go,christopher-henderson/Go,akutz/go,cloudflare/go,akutz/go,vsekhar/elastic-go,vsekhar/elastic-go,nawawi/go,linux-on-ibm-z/go,CAFxX/go,vsekhar/elastic-go,Cofyc/go,derekmarcotte/go,derekmarcotte/go,golang/go,polyverse-security/go,golang/go,codestation/go,derekmarcotte/go,linux-on-ibm-z/go,nawawi/go,Cofyc/go,CAFxX/go,nawawi/go,CAFxX/go,polyverse-security/go,polyverse-security/go,codestation/go,cloudflare/go,vsekhar/elastic-go,cloudflare/go,codestation/go,golang/go,codestation/go,cloudflare/go,akutz/go,linux-on-ibm-z/go,golang/go,derekmarcotte/go,Cofyc/go,derekmarcotte/go,akutz/go,nawawi/go,golang/go,vsekhar/elastic-go,cloudflare/go,ImJasonH/go,codestation/go,vsekhar/elastic-go,ImJasonH/go,josharian/go,cloudflare/go,ImJasonH/go,codestation/go,linux-on-ibm-z/go,polyverse-security/go,Cofyc/go,Cofyc/go,nawawi/go,josharian/go,josharian/go,ImJasonH/go,CAFxX/go,nawawi/go,akutz/go,akutz/go,derekmarcotte/go,ImJasonH/go,polyverse-security/go,josharian/go,josharian/go,nawawi/go,derekmarcotte/go,polyverse-security/go,Cofyc/go,CAFxX/go,josharian/go,cloudflare/go,golang/go,golang/go,polyverse-security/go,polyverse-security/go,codestation/go,linux-on-ibm-z/go,ImJasonH/go,ImJasonH/go,Cofyc/go,CAFxX/go,ImJasonH/go,golang/go,akutz/go,josharian/go,Cofyc/go,josharian/go,CAFxX/go,CAFxX/go,cloudflare/go,vsekhar/elastic-go,derekmarcotte/go,linux-on-ibm-z/go,nawawi/go,vsekhar/elastic-go