cmd/compile: update and reenable Formats test
cmd/compile: update and reenable Formats test

Change-Id: I9c0da13d21551dbf766156472224370ab9badfe9
Reviewed-on: https://go-review.googlesource.com/28778
Run-TryBot: Robert Griesemer <a6752097faebf1f02d80107d77a9be009089afe3@golang.org>
Reviewed-by: Matthew Dempsky <e56ac2c500064424afac424d4b5e53bd0570a731@google.com>

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