cmd/internal/obj/arm64: adjust literal pool flush for span-dependent jump enlargement
cmd/internal/obj/arm64: adjust literal pool flush for span-dependent jump enlargement

The current code delays the literal pool until the very last moment,
but based on the assumption that span-dependent jumps are as
short as possible. If they need to be enlarged in a later round, that
very last moment may be too late. Flush a little early to prevent that.

Fixes #13579.

Change-Id: I759b5db5c43a977bf2b940872870cbbc436ad141
Reviewed-on: https://go-review.googlesource.com/18972
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
Reviewed-by: Dave Cheney <bfcdf3e6ca6cef45543bfbb57509c92aec9a39fb@cheney.net>
Run-TryBot: Russ Cox <5ad239cb8a44f659eaaee0aa1ea5b94947abe557@golang.org>

akutz/go,ImJasonH/go,codestation/go,suncycheng/go,cloudflare/go,codestation/go,Samurais/go,4ad/go,vsekhar/elastic-go,theif519/go,binarycrusader/go,Cofyc/go,christopher-henderson/Go,golang/go,cloudflare/go,miolini/go,binarycrusader/go,Cofyc/go,nawawi/go,Endika/go,polyverse-security/go,derekmarcotte/go,codestation/go,sndnvaps/go,codestation/go,goodlang/good,polyverse-security/go,suncycheng/go,ganboing/go-esx,vsekhar/elastic-go,Endika/go,Cofyc/go,josharian/go,theif519/go,CAFxX/go,Samurais/go,mwhudson/go,CAFxX/go,akutz/go,vanloswang/go,theif519/go,ganboing/go-esx,josharian/go,sndnvaps/go,binarycrusader/go,sndnvaps/go,theif519/go,CAFxX/go,Endika/go,Samurais/go,ImJasonH/go,codestation/go,Endika/go,Cofyc/go,mwhudson/go,4ad/go,nawawi/go,linux-on-ibm-z/go,codestation/go,josharian/go,momchil-velikov/go,josharian/go,suncycheng/go,mwhudson/go,akutz/go,goodlang/good,vanloswang/go,vsekhar/elastic-go,derekmarcotte/go,akutz/go,Endika/go,4ad/go,linux-on-ibm-z/go,derekmarcotte/go,Cofyc/go,goodlang/good,Samurais/go,4ad/go,akutz/go,nawawi/go,vsekhar/elastic-go,ganboing/go-esx,derekmarcotte/go,cloudflare/go,CAFxX/go,sndnvaps/go,nawawi/go,mwhudson/go,goodlang/good,mwhudson/go,derekmarcotte/go,Cofyc/go,ImJasonH/go,vanloswang/go,vsekhar/elastic-go,suncycheng/go,ganboing/go-esx,nawawi/go,nawawi/go,vsekhar/elastic-go,miolini/go,golang/go,vanloswang/go,golang/go,linux-on-ibm-z/go,vsekhar/elastic-go,josharian/go,cloudflare/go,mwhudson/go,Samurais/go,miolini/go,codestation/go,momchil-velikov/go,momchil-velikov/go,binarycrusader/go,cloudflare/go,Samurais/go,theif519/go,momchil-velikov/go,linux-on-ibm-z/go,derekmarcotte/go,golang/go,mwhudson/go,Endika/go,4ad/go,golang/go,akutz/go,cloudflare/go,ganboing/go-esx,miolini/go,golang/go,goodlang/good,binarycrusader/go,vanloswang/go,ganboing/go-esx,4ad/go,linux-on-ibm-z/go,Cofyc/go,ganboing/go-esx,theif519/go,momchil-velikov/go,suncycheng/go,cloudflare/go,Samurais/go,polyverse-security/go,goodlang/good,binarycrusader/go,CAFxX/go,suncycheng/go,linux-on-ibm-z/go,polyverse-security/go,josharian/go,linux-on-ibm-z/go,ImJasonH/go,golang/go,derekmarcotte/go,polyverse-security/go,linux-on-ibm-z/go,goodlang/good,polyverse-security/go,akutz/go,CAFxX/go,Cofyc/go,vanloswang/go,polyverse-security/go,binarycrusader/go,akutz/go,binarycrusader/go,miolini/go,sndnvaps/go,codestation/go,miolini/go,cloudflare/go,sndnvaps/go,goodlang/good,miolini/go,ImJasonH/go,golang/go,suncycheng/go,sndnvaps/go,CAFxX/go,ImJasonH/go,nawawi/go,vsekhar/elastic-go,miolini/go,mwhudson/go,momchil-velikov/go,suncycheng/go,josharian/go,momchil-velikov/go,vanloswang/go,sndnvaps/go,theif519/go,ImJasonH/go,4ad/go,CAFxX/go,vanloswang/go,4ad/go,Samurais/go,josharian/go,theif519/go,ganboing/go-esx,Endika/go,ImJasonH/go,nawawi/go,Endika/go,derekmarcotte/go,polyverse-security/go,momchil-velikov/go