cue/ast: allow CommentGroups in NewStruct
cue/ast: allow CommentGroups in NewStruct

Change-Id: I1808763b88e4b249a7db470f8b26507aafa3c130
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/5082
Reviewed-by: Marcel van Lohuizen <a22d082192f3ccf984644a4f482781f4c2d65180@golang.org>

cuelang/cue