cue/ast/astutil: remove deprecated API usage

This removes some deprecated API usages in the astutil package.

While here, fix a typo and some unordered imports.

Updates #2480.

Signed-off-by: Noam Dolovich <noam.tzvi.dolovich@gmail.com>
Change-Id: I3a4f424379a1bdb7e82c67841f891e292f3f0d09
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1194643
TryBot-Result: CUEcueckoo <cueckoo@cuelang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Unity-Result: CUE porcuepine <cue.porcuepine@gmail.com>

cue/ast/astutil/apply.go

@@ -450,7 +450,7 @@ func (f *applier) Before(c Cursor) applyVisitor {
 	node := c.Node()
 	if f.before == nil || (f.before(c) && node == c.Node()) {
 		f.commentStack = append(f.commentStack, f.current)
-		f.current = commentFrame{cg: node.Comments()}
+		f.current = commentFrame{cg: ast.Comments(node)}
 		f.visitComments(c, f.current.pos)
 		return f
 	}

cue/ast/astutil/file_test.go

@@ -23,6 +23,7 @@ import (
 	"cuelang.org/go/cue"
 	"cuelang.org/go/cue/ast"
 	"cuelang.org/go/cue/ast/astutil"
+	"cuelang.org/go/cue/cuecontext"
 	"cuelang.org/go/cue/format"
 	"cuelang.org/go/cue/token"
 	_ "cuelang.org/go/pkg"
@@ -80,14 +81,12 @@ func TestToFile(t *testing.T) {
 				t.Fatal(err)
 			}
 
-			var r cue.Runtime
-
-			inst, err := r.CompileFile(f)
-			if err != nil {
+			v := cuecontext.New().BuildFile(f)
+			if err := v.Err(); err != nil {
 				t.Fatal(err)
 			}
 
-			b, err := format.Node(inst.Value().Syntax(cue.Concrete(true)))
+			b, err := format.Node(v.Syntax(cue.Concrete(true)))
 			if err != nil {
 				t.Fatal(err)
 			}

cue/ast/astutil/sanitize.go

@@ -31,7 +31,7 @@ import (
 // - change a predeclared identifier reference to use the __ident form,
 //   instead of introducing an alias.
 
-// Sanitize rewrites File f in place to be well formed after automated
+// Sanitize rewrites File f in place to be well-formed after automated
 // construction of an AST.
 //
 // Rewrites:

cue/ast/astutil/util.go

@@ -78,7 +78,7 @@ func CopyComments(to, from ast.Node) {
 	if from == nil {
 		return
 	}
-	ast.SetComments(to, from.Comments())
+	ast.SetComments(to, ast.Comments(from))
 }
 
 // CopyPosition sets the position of one node to another.
@@ -95,7 +95,7 @@ func CopyMeta(to, from ast.Node) ast.Node {
 	if from == nil {
 		return to
 	}
-	ast.SetComments(to, from.Comments())
+	ast.SetComments(to, ast.Comments(from))
 	ast.SetPos(to, from.Pos())
 	return to
 }

cue/ast/astutil/util_test.go

@@ -18,8 +18,9 @@ import (
 	"path"
 	"testing"
 
-	"cuelang.org/go/cue/ast"
 	"github.com/google/go-cmp/cmp"
+
+	"cuelang.org/go/cue/ast"
 )
 
 func TestImportInfo(t *testing.T) {