cue: Value.Kind returns BottomKind for open lists

[rogpeppe]

What version of CUE are you using (cue version)?

95fd2e94f633c9c32365a6938aac422d1ab48bff

Does this issue reproduce with the latest stable release?

Yes

What did you do?

exec go mod tidy
exec go run .
stdout 'list'
-- go.mod --
module test

require (
	cuelang.org/go v0.11.0-alpha.3.0.20241007084123-95fd2e94f633
)
-- main.go --
package main

import (
	"fmt"

	"cuelang.org/go/cue/cuecontext"
)

func main() {
	ctx := cuecontext.New()
	v := ctx.CompileString(`[1, 2, ...]`)
	if v.Err() != nil {
		panic(v.Err())
	}
	fmt.Println(v.Kind())
}

What did you expect to see?

Passing test. The open list [1, 2, ...] is just as "concrete" as any open struct.

What did you see instead?

> exec go mod tidy
> exec go run .
[stdout]
_|_
> stdout 'list'
FAIL: /tmp/y.txtar:3: no match for `list` found in stdout