Test of "too new" diagnostics from the stdversion analyzer.

This test references go1.21 symbols from std, but the analyzer itself
depends on the go1.22 behavior of versions.FileVersion.

See also go/analysis/passes/stdversion/testdata/test.txtar,
which runs the same test in the analysistest framework.

-- flags --
-min_go=go1.22

-- go.mod --
module example.com

go 1.21

-- a/a.go --
package a

import "go/types"

func _() {
	// old package-level type
	var _ types.Info // ok: defined by go1.0

	// new field of older type
	_ = new(types.Info).FileVersions //@diag("FileVersions", re`types.FileVersions requires go1.22 or later \(module is go1.21\)`)

	// new method of older type
	_ = new(types.Info).PkgNameOf //@diag("PkgNameOf", re`types.PkgNameOf requires go1.22 or later \(module is go1.21\)`)

	// new package-level type
	var a types.Alias //@diag("Alias", re`types.Alias requires go1.22 or later \(module is go1.21\)`)

	// new method of new type
	a.Underlying() // no diagnostic
}

-- sub/go.mod --
module example.com/sub

go 1.21

-- sub/sub.go --
package sub

import "go/types"

func _() {
	// old package-level type
	var _ types.Info // ok: defined by go1.0

	// new field of older type
	_ = new(types.Info).FileVersions //@diag("FileVersions", re`types.FileVersions requires go1.22 or later \(module is go1.21\)`)

	// new method of older type
	_ = new(types.Info).PkgNameOf //@diag("PkgNameOf", re`types.PkgNameOf requires go1.22 or later \(module is go1.21\)`)

	// new package-level type
	var a types.Alias //@diag("Alias", re`types.Alias requires go1.22 or later \(module is go1.21\)`)

	// new method of new type
	a.Underlying() // no diagnostic
}

-- sub/tagged.go --
//go:build go1.22

package sub

import "go/types"

func _() {
	// old package-level type
	var _ types.Info

	// new field of older type
	_ = new(types.Info).FileVersions

	// new method of older type
	_ = new(types.Info).PkgNameOf

	// new package-level type
	var a types.Alias

	// new method of new type
	a.Underlying()
}