Add a reduced text test-case for issue 4665

Re: issue 4665 and PR 6601.

Since we currently don't have a good `text` test-case that fails without the above PR, this patch adds a reduced one.

test/pdfs/.gitignore

@@ -7,6 +7,7 @@
 !xref_command_missing.pdf
 !issue2391-1.pdf
 !issue2391-2.pdf
+!issue4665.pdf
 !issue5801.pdf
 !issue5972.pdf
 !issue5874.pdf

test/test_manifest.json

@@ -492,6 +492,13 @@
        "type": "eq",
        "about": "PDF with annotations, some of which have the Hidden flag set."
     },
+    {  "id": "issue4665-text",
+       "file": "pdfs/issue4665.pdf",
+       "md5": "0de1308432819c101881df7ca4424575",
+       "rounds": 1,
+       "link": false,
+       "type": "text"
+    },
     {  "id": "fit11-talk",
        "file": "pdfs/fit11-talk.pdf",
        "md5": "eb7b224107205db4fea9f7df0185f77d",