fix debug/1 function to be available only when debug/0 is defined

builtin.jq

@@ -160,7 +160,6 @@ def sub($re; str; $flags):
 def gsub($re; str): sub($re; str; "g");
 def gsub($re; str; $flags): sub($re; str; $flags + "g");
 
-def debug(f): (f | debug | empty), .;
 def inputs:
   try
     repeat(input)

compiler.go

@@ -993,6 +993,22 @@ func (c *compiler) compileFunc(e *Func) error {
 				true,
 				-1,
 			)
+		case "debug":
+			setfork := c.lazy(func() *code {
+				return &code{op: opfork, v: len(c.codes)}
+			})
+			if err := c.compileQuery(e.Args[0]); err != nil {
+				return err
+			}
+			if err := c.compileFunc(&Func{Name: "debug"}); err != nil {
+				if _, ok := err.(*funcNotFoundError); ok {
+					err = &funcNotFoundError{e}
+				}
+				return err
+			}
+			c.append(&code{op: opbacktrack})
+			setfork()
+			return nil
 		default:
 			return c.compileCall(e.Name, e.Args)
 		}

compiler_test.go

@@ -353,8 +353,6 @@ func BenchmarkCompile(b *testing.B) {
 		_, err := gojq.Compile(
 			query,
 			gojq.WithInputIter(gojq.NewIter()),
-			gojq.WithFunction("debug", 0, 0,
-				func(v any, _ []any) any { return v }),
 		)
 		if err != nil {
 			b.Fatal(err)

func.go

@@ -51,6 +51,7 @@ func init() {
 		"builtins":       argFunc0(nil),
 		"input":          argFunc0(nil),
 		"modulemeta":     argFunc0(nil),
+		"debug":          argFunc1(nil),
 		"abs":            argFunc0(funcAbs),
 		"length":         argFunc0(funcLength),
 		"utf8bytelength": argFunc0(funcUtf8ByteLength),