doc/go1.7.html: add known issues section for FreeBSD crashes
doc/go1.7.html: add known issues section for FreeBSD crashes

Updates #16396

Change-Id: I7b4f85610e66f2c77c17cf8898cc41d81b2efc8c
Reviewed-on: https://go-review.googlesource.com/25283
Reviewed-by: Chris Broadfoot <0c2851a4f8ab4aa5606e69c0757771dd13dbe686@golang.org>
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
Reviewed-by: Andrew Gerrand <395a7d33bec8475c9b83b7d440f141bcbd994aa5@golang.org>

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