emacs-29 c0fe6c72ce 7/9: Improve dockerfile-ts-mode imenu generation (Bug#59979)

[Yuan Fu]

branch: emacs-29
commit c0fe6c72cec477fdd2494bf3d26ab75790d2f720
Author: Randy Taylor <dev@rjt.dev>
Commit: Yuan Fu <casouri@gmail.com>

    Improve dockerfile-ts-mode imenu generation (Bug#59979)
    
    * lisp/progmodes/dockerfile-ts-mode.el (treesit-node-child-by-field-name):
    Declare.
    (dockerfile-ts-mode--imenu-1): Use stage name if available.
---
 lisp/progmodes/dockerfile-ts-mode.el | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/lisp/progmodes/dockerfile-ts-mode.el 
b/lisp/progmodes/dockerfile-ts-mode.el
index 544e0f82d6..40d90cc2df 100644
--- a/lisp/progmodes/dockerfile-ts-mode.el
+++ b/lisp/progmodes/dockerfile-ts-mode.el
@@ -33,6 +33,7 @@
 (declare-function treesit-parser-create "treesit.c")
 (declare-function treesit-induce-sparse-tree "treesit.c")
 (declare-function treesit-node-child "treesit.c")
+(declare-function treesit-node-child-by-field-name "treesit.c")
 (declare-function treesit-node-start "treesit.c")
 (declare-function treesit-node-type "treesit.c")
 
@@ -117,8 +118,10 @@ the subtrees."
                            children))
          (name (when ts-node
                  (pcase (treesit-node-type ts-node)
-                   ("from_instruction" (treesit-node-text
-                                        (treesit-node-child ts-node 1) t)))))
+                   ("from_instruction"
+                    (treesit-node-text
+                     (or (treesit-node-child-by-field-name ts-node "as")
+                         (treesit-node-child ts-node 1)) t)))))
          (marker (when ts-node
                    (set-marker (make-marker)
                                (treesit-node-start ts-node)))))