Repository: go
Issue: x/tools/gopls: semantic tokens: highlight control flow tokens
Labels: help wanted,FeatureRequest,gopls,Tools

### gopls version

Build info
----------
golang.org/x/tools/gopls v0.15.3
    golang.org/x/tools/gopls@v0.15.3 h1:zbdOidFrPTc8Bx0YrN5QKgJ0zCjyGi0L27sKQ/bDG5o=
    github.com/BurntSushi/toml@v1.2.1 h1:9F2/+DoOYIOksmaJFPw1tGFy1eDnIJXg+UHjuD8lTak=
    github.com/google/go-cmp@v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
    golang.org/x/exp/typeparams@v0.0.0-20221212164502-fae10dda9338 h1:2O2DON6y3XMJiQRAS1UWU+54aec2uopH3x7MAiqGW6Y=
    golang.org/x/mod@v0.15.0 h1:SernR4v+D55NyBH2QiEQrlBAnj1ECL6AGrA5+dPaMY8=
    golang.org/x/sync@v0.6.0 h1:5BMeUDZ7vkXGfEr1x9B4bRcTH4lpkTkpdh0T/J+qjbQ=
    golang.org/x/telemetry@v0.0.0-20240209200032-7b892fcb8a78 h1:vcVnuftN4J4UKLRcgetjzfU9FjjgXUUYUc3JhFplgV4=
    golang.org/x/text@v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
    golang.org/x/tools@v0.18.1-0.20240412183611-d92ae0781217 h1:uH9jJYgeLCvblH0S+03kFO0qUDxRkbLRLFiKVVDl7ak=
    golang.org/x/vuln@v1.0.1 h1:KUas02EjQK5LTuIx1OylBQdKKZ9jeugs+HiqO5HormU=
    honnef.co/go/tools@v0.4.6 h1:oFEHCKeID7to/3autwsWfnuv69j3NsfcXbvJKuIcep8=
    mvdan.cc/gofumpt@v0.6.0 h1:G3QvahNDmpD+Aek/bNOLrFR2XC6ZAdo62dZu65gmwGo=
    mvdan.cc/xurls/v2@v2.5.0 h1:lyBNOm8Wo71UknhUs4QTFUNNMyxy2JEIaKKo0RWOh+8=
go: go1.22.3

### go env

```shell
GO111MODULE=''
GOARCH='arm64'
GOBIN=''
GOCACHE='/Users/jmgd/Library/Caches/go-build'
GOENV='/Users/jmgd/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMODCACHE='/Users/jmgd/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='darwin'
GOPATH='/Users/jmgd/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.22.3'
GCCGO='gccgo'
AR='ar'
CC='clang'
CXX='clang++'
CGO_ENABLED='1'
GOMOD='/dev/null'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/4d/v4vg0mc15_gf9skpnjgmmhdm0000gn/T/go-build2911028327=/tmp/go-build -gno-record-gcc-switches -fno-common'
```


### What did you do?

Write code with some sort of control flow:
```go
func controlFlow(i int64) {
    if i < 0 {
        return true
    } else {
        return false
    }
}
```

### What did you see happen?

`return`, `if` and `else` (i.e. control flow keywords) are marked as `keyword` only, while the TextMate grammar already has support for control flow
<img width="571" alt="Screenshot 2024-05-27 at 08 49 34" src="https://github.com/golang/go/assets/15343819/9cbb3e83-8f21-4eeb-a51c-18c7abea187d">


### What did you expect to see?

The `controlFlow` modifier along with the respective keywords, like in this Rust example
<img width="488" alt="Screenshot 2024-05-27 at 08 50 38" src="https://github.com/golang/go/assets/15343819/0029d30e-d405-4ec5-80bc-7ec06164c51f">


### Editor and settings

```
  "go.toolsManagement.autoUpdate": true,
  "gopls": {
    "ui.semanticTokens": true
  },
```

### Logs

_No response_