cmd/link: fix size of filetab slice
cmd/link: fix size of filetab slice

The linker writes the number of file symbols (Nhistfile) to the filetab slice
and then Nhistfile offsets -- which means the slice contains Nhistfile+1
entries, not just Nhistfile.

I think this bug has been around since at least 1.4 but it's easier to trigger
with shared libraries and a tiny binary that only has a couple of functions in
it -- try go install -buildmode=shared std && go run -linkshared test/fixedbugs/issue4388.go.

Change-Id: I6c0f01f1e607b9b2b96872e37ffce81281911504
Reviewed-on: https://go-review.googlesource.com/16342
Run-TryBot: Michael Hudson-Doyle <5e87ffb38a52af6fb9a19b679e9122c7a4d601a5@canonical.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

vsekhar/elastic-go,Endika/go,vanloswang/go,Samurais/go,vsekhar/elastic-go,Jordanzuo/go,deft-code/go,codestation/go,kim-racktop/go,4ad/go,akutz/go,momchil-velikov/go,vanloswang/go,Endika/go,theif519/go,linux-on-ibm-z/go,suncycheng/go,nawawi/go,Samurais/go,derekmarcotte/go,cloudflare/go,4ad/go,nawawi/go,miolini/go,nawawi/go,sndnvaps/go,golang/go,deft-code/go,ganboing/go-esx,akutz/go,cloudflare/go,Endika/go,Cofyc/go,mwhudson/go,cyberroadie/go,golang/go,Cofyc/go,binarycrusader/go,Jordanzuo/go,ganboing/go-esx,cloudflare/go,ImJasonH/go,fjballest/golang,polyverse-security/go,roth1002/go,mwhudson/go,theif519/go,ganboing/go-esx,theif519/go,linux-on-ibm-z/go,codestation/go,fjballest/golang,akutz/go,goodlang/good,derekmarcotte/go,4ad/go,fjballest/golang,akutz/go,nawawi/go,Samurais/go,suncycheng/go,cloudflare/go,suncycheng/go,polyverse-security/go,Samurais/go,kim-racktop/go,sndnvaps/go,odeke-em/go,momchil-velikov/go,cyberroadie/go,rachtsingh/gogojuice,CAFxX/go,ganboing/go-esx,vsekhar/elastic-go,ganboing/go-esx,miolini/go,rachtsingh/gogojuice,kim-racktop/go,mwhudson/go,codestation/go,Endika/go,Jordanzuo/go,Jordanzuo/go,cloudflare/go,nawawi/go,momchil-velikov/go,goodlang/good,Samurais/go,binarycrusader/go,Samurais/go,nawawi/go,cloudflare/go,ganboing/go-esx,goodlang/good,Cofyc/go,miolini/go,vanloswang/go,derekmarcotte/go,Cofyc/go,sndnvaps/go,momchil-velikov/go,roth1002/go,josharian/go,golang/go,golang/go,odeke-em/go,rachtsingh/gogojuice,derekmarcotte/go,goodlang/good,codestation/go,deft-code/go,josharian/go,fjballest/golang,derekmarcotte/go,binarycrusader/go,Jordanzuo/go,4ad/go,sndnvaps/go,odeke-em/go,suncycheng/go,fjballest/golang,josharian/go,mwhudson/go,vsekhar/elastic-go,roth1002/go,theif519/go,vanloswang/go,codestation/go,vsekhar/elastic-go,goodlang/good,odeke-em/go,cloudflare/go,binarycrusader/go,kim-racktop/go,akutz/go,CAFxX/go,Jordanzuo/go,miolini/go,vanloswang/go,vanloswang/go,vanloswang/go,ganboing/go-esx,polyverse-security/go,josharian/go,cyberroadie/go,roth1002/go,goodlang/good,josharian/go,polyverse-security/go,Cofyc/go,deft-code/go,CAFxX/go,roth1002/go,cyberroadie/go,rachtsingh/gogojuice,roth1002/go,CAFxX/go,ImJasonH/go,josharian/go,momchil-velikov/go,josharian/go,CAFxX/go,nawawi/go,nawawi/go,codestation/go,akutz/go,suncycheng/go,sndnvaps/go,Cofyc/go,Samurais/go,suncycheng/go,ImJasonH/go,Cofyc/go,cyberroadie/go,codestation/go,linux-on-ibm-z/go,ImJasonH/go,deft-code/go,Endika/go,Jordanzuo/go,golang/go,CAFxX/go,ImJasonH/go,fjballest/golang,golang/go,mwhudson/go,christopher-henderson/Go,vsekhar/elastic-go,linux-on-ibm-z/go,CAFxX/go,Endika/go,theif519/go,ImJasonH/go,4ad/go,ImJasonH/go,cloudflare/go,sndnvaps/go,Endika/go,momchil-velikov/go,miolini/go,goodlang/good,polyverse-security/go,derekmarcotte/go,miolini/go,cyberroadie/go,vsekhar/elastic-go,polyverse-security/go,mwhudson/go,vsekhar/elastic-go,CAFxX/go,golang/go,odeke-em/go,theif519/go,roth1002/go,binarycrusader/go,binarycrusader/go,kim-racktop/go,mwhudson/go,kim-racktop/go,binarycrusader/go,theif519/go,rachtsingh/gogojuice,miolini/go,cyberroadie/go,momchil-velikov/go,golang/go,suncycheng/go,odeke-em/go,rachtsingh/gogojuice,linux-on-ibm-z/go,linux-on-ibm-z/go,miolini/go,theif519/go,ImJasonH/go,polyverse-security/go,derekmarcotte/go,sndnvaps/go,deft-code/go,linux-on-ibm-z/go,odeke-em/go,Cofyc/go,rachtsingh/gogojuice,derekmarcotte/go,goodlang/good,momchil-velikov/go,polyverse-security/go,deft-code/go,mwhudson/go,rachtsingh/gogojuice,odeke-em/go,deft-code/go,codestation/go,Endika/go,Jordanzuo/go,vanloswang/go,fjballest/golang,suncycheng/go,kim-racktop/go,ganboing/go-esx,roth1002/go,akutz/go,kim-racktop/go,binarycrusader/go,4ad/go,Samurais/go,sndnvaps/go,4ad/go,josharian/go,cyberroadie/go,linux-on-ibm-z/go,4ad/go,akutz/go,fjballest/golang