x/tools/gopls: Completion: add description to suggested function literals

gopls version

v0.18.1

go env

AR='ar'
CC='clang'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='clang++'
GCCGO='gccgo'
GO111MODULE=''
GOARCH='arm64'
GOARM64='v8.0'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/Users/yuchen.xie/Library/Caches/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/Users/yuchen.xie/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/28/7sypdf0519xfl4ylhq_90s0m0000gp/T/go-build3549002889=/tmp/go-build -gno-record-gcc-switches -fno-common'
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMOD='/Users/yuchen.xie/workspace/promotion-discount-search/go.mod'
GOMODCACHE='/Users/yuchen.xie/gopath/pkg/mod'
GONOPROXY='git.garena.com'
GONOSUMDB='git.garena.com'
GOOS='darwin'
GOPATH='/Users/yuchen.xie/gopath'
GOPRIVATE='git.garena.com'
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='on'
GOTELEMETRYDIR='/Users/yuchen.xie/Library/Application Support/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.24.2'
GOWORK=''
PKG_CONFIG='pkg-config'

What did you do?

Type go fu to trigger a go routine.

What did you see happen?

I saw some suggestions, without any descriptions and I don't know what are the differences among them.

What did you expect to see?

I expected here should have a description. Note that what are the suggestions doesn't matter here.

Editor and settings

No response

Logs

No response