x/tools/gopls: rename also renames qualified identifiers in a doc comment

[myitcv]

What version of Go are you using (go version)?

$ go version
go version devel +8869086d8f Thu Feb 4 04:46:49 2021 +0000 linux/amd64
$ go list -m golang.org/x/tools
golang.org/x/tools v0.1.1-0.20210204180613-842a9283d6c6
$ go list -m golang.org/x/tools/gopls
golang.org/x/tools/gopls v0.0.0-20210204180613-842a9283d6c6

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/myitcv/.cache/go-build"
GOENV="/home/myitcv/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/myitcv/gostuff/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/myitcv/gostuff"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/myitcv/gos"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/myitcv/gos/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="devel +8869086d8f Thu Feb 4 04:46:49 2021 +0000"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/myitcv/.vim/plugged/govim/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build2716400008=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Start with:

-- blah/blah.go --
package blah

const Name = "blah"
-- go.mod --
module blah.com

go 1.16
-- main.go --
package main

import (
	"fmt"

	"blah.com/blah"
)

func main() {
	fmt.Println(Name())
}

// Name returns blah.Name
func Name() string {
	return blah.Name
}

• Open Vim (which launches govim and gopls)
• Move the cursor over Name of func Name() string
• Rename to Other

What did you expect to see?

The doc comment as follows:

// Other returns blah.Name

What did you see instead?

// Other returns blah.Other

Log files:

• gopls.log
• govim.log

---

cc @stamblerre

FYI @leitzler