chore: remove perl, make and local docs. (#476)

Remove the dependencies on perl and make.

inline.pl is replaced by tools/gen-jscore and token/tokenfmt is replaced
by tools/gen-tokens which are both golang text/template utilities.

gen-jscore uses property ordering that matches chromes output ordering
adding missing properties to the Error types.

Local generated documentation have been removed as https://pkg.go.dev/
is more feature rich.

The use of make has been removed as the functionality is now replicated by
standard golang tools go test ./... and go generate ./... as well as integrated
into github actions.

tools/gen-tokens/main.go

@@ -0,0 +1,83 @@
+// Command gen-tokens generates go representations of JavaScript tokens.
+package main
+
+import (
+	"embed"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"os/exec"
+	"strings"
+	"text/template"
+
+	"gopkg.in/yaml.v3"
+)
+
+//go:embed .gen-tokens.yaml
+var configData []byte
+
+//go:embed templates/*
+var templates embed.FS
+
+// token represents a JavaScript token.
+type token struct {
+	Group  string `yaml:"group"`
+	Name   string `yaml:"name"`
+	Symbol string `yaml:"symbol"`
+	Future bool   `yaml:"future"`
+	Strict bool   `yaml:"strict"`
+}
+
+// config represents our configuration.
+type config struct {
+	Tokens []token `yaml:"tokens"`
+}
+
+// generate generates the context file writing the output to filename.
+func generate(filename string) (err error) {
+	var cfg config
+	if err := yaml.Unmarshal(configData, &cfg); err != nil {
+		return fmt.Errorf("decode config: %w", err)
+	}
+
+	tmpl := template.New("base").Funcs(template.FuncMap{
+		"toLower": strings.ToLower,
+	})
+
+	tmpl, err = tmpl.ParseFS(templates, "templates/*.tmpl")
+	if err != nil {
+		return fmt.Errorf("parse templates: %w", err)
+	}
+
+	output, err := os.Create(filename) //nolint: gosec
+	if err != nil {
+		return fmt.Errorf("open output: %w", err)
+	}
+
+	defer func() {
+		if errc := output.Close(); err == nil && errc != nil {
+			err = errc
+		}
+	}()
+
+	if err := tmpl.ExecuteTemplate(output, "root.tmpl", cfg); err != nil {
+		return fmt.Errorf("execute template: %w", err)
+	}
+
+	cmd := exec.Command("gofmt", "-w", filename)
+	buf, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("format output %q: %w", string(buf), err)
+	}
+
+	return nil
+}
+
+func main() {
+	var filename string
+	flag.StringVar(&filename, "output", "token_const.go", "the filename to write the generated code to")
+	if err := generate(filename); err != nil {
+		log.Fatal(err)
+	}
+}