doc/go1.15: include changes in net/http/pprof and runtime/pprof
doc/go1.15: include changes in net/http/pprof and runtime/pprof

net/http/pprof: delta profile support
runtime/pprof: profile labels plumbing for goroutine profiles

Change-Id: I92e750dc894c8c6b3c3ba10f7be58bb541d3c289
Reviewed-on: https://go-review.googlesource.com/c/go/+/230023
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

cloudflare/go,cloudflare/go,golang/go,cloudflare/go,cloudflare/go,CAFxX/go,nawawi/go,cloudflare/go,CAFxX/go,golang/go,nawawi/go,nawawi/go,nawawi/go,CAFxX/go,golang/go,CAFxX/go,CAFxX/go,akutz/go,CAFxX/go,golang/go,CAFxX/go,cloudflare/go,nawawi/go,nawawi/go,golang/go,akutz/go,akutz/go,akutz/go,akutz/go,golang/go,CAFxX/go,cloudflare/go,nawawi/go,golang/go,cloudflare/go,golang/go,nawawi/go,akutz/go,akutz/go,akutz/go