Add reference tests for SimFang variant and XiaoBiaoSong fonts

Add eq tests for the two newly supported Chinese font name variants
(仿宋体 and 小标宋) to verify correct GBK encoding detection.

Author: pengkunbin

test/pdfs/.gitignore

@@ -16,6 +16,7 @@
 !bug1727053.pdf
 !issue18408_reduced.pdf
 !bug1907000_reduced.pdf
+!SimFang-variant.pdf
 !bug1953099.pdf
 !issue11913.pdf
 !issue2391-1.pdf
@@ -81,6 +82,7 @@
 !issue7835.pdf
 !issue11922_reduced.pdf
 !issue7855.pdf
+!XiaoBiaoSong.pdf
 !issue11144_reduced.pdf
 !issue7872.pdf
 !issue7901.pdf

test/pdfs/SimFang-variant.pdf

@@ -13971,5 +13971,19 @@
     "md5": "ead167e0328f1a1f4f8901cee501a9c4",
     "rounds": 1,
     "type": "eq"
+  },
+  {
+    "id": "SimFang-variant",
+    "file": "pdfs/SimFang-variant.pdf",
+    "md5": "d412460812cd940917091e8975620faf",
+    "rounds": 1,
+    "type": "eq"
+  },
+  {
+    "id": "XiaoBiaoSong",
+    "file": "pdfs/XiaoBiaoSong.pdf",
+    "md5": "7072f6763bf2f0d6df14d5fc86962c5a",
+    "rounds": 1,
+    "type": "eq"
   }
 ]