patch 9.1.0619: tests: test_popup fails

Problem:  tests: test_popup fails
          (after v9.1.0618)
Solution: Correct test, move combining extra attributes to
          pum_compute_text_attrs() (glepnir)

closes: #15353

Signed-off-by: glepnir <glephunter@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_popup.vim b/src/testdir/test_popup.vim
index 30cabf9..67e600c 100644
--- a/src/testdir/test_popup.vim
+++ b/src/testdir/test_popup.vim
@@ -1509,9 +1509,9 @@
       endif
       return {
             \ 'words': [
-            \ { 'word': 'aword1', 'menu': 'extra text 1', 'kind': 'W', 'extrahl': 'StrikeFake' },
+            \ { 'word': 'aword1', 'menu': 'extra text 1', 'kind': 'W', 'hl_group': 'StrikeFake' },
             \ { 'word': 'aword2', 'menu': 'extra text 2', 'kind': 'W', },
-            \ { 'word': '你好', 'menu': 'extra text 3', 'kind': 'W', 'extrahl': 'StrikeFake' },
+            \ { 'word': '你好', 'menu': 'extra text 3', 'kind': 'W', 'hl_group': 'StrikeFake' },
             \]}
     endfunc
     set completeopt=menu