go/ast: fix comments misinterpreted as documentation
go/ast: fix comments misinterpreted as documentation

The comments describing blocks of Pos/End implementations for various
nodes types are being misinterpreted as documentation for BadDecl,
BadExpr, BadStmt, and ImportSpec's Pos methods.

Change-Id: I935b0bc38dbc13e9305f3efeb437dd3a6575d9a1
Reviewed-on: https://go-review.googlesource.com/24152
Reviewed-by: Robert Griesemer <a6752097faebf1f02d80107d77a9be009089afe3@golang.org>

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