For non-embedded fonts, map softhyphen (0x00AD) to regular hyphen (0x002D) (issue 9084)

In the PDF file, the `ToUnicode` data first maps the hyphen correctly, and then *overwrites* it to point to the softhyphen instead. That one cannot be rendered in browsers, and an empty space thus appear instead.

Fixes 9084.

test/pdfs/.gitignore

@@ -62,6 +62,7 @@
 !issue8707.pdf
 !issue8798r.pdf
 !issue8823.pdf
+!issue9084.pdf
 !bad-PageLabels.pdf
 !filled-background.pdf
 !ArabicCIDTrueType.pdf

test/test_manifest.json

@@ -711,6 +711,13 @@
        "link": false,
        "type": "eq"
     },
+    {  "id": "issue9084",
+       "file": "pdfs/issue9084.pdf",
+       "md5": "5570ec01cc869d299fec1b2f68926a08",
+       "rounds": 1,
+       "link": false,
+       "type": "eq"
+    },
     {  "id": "issue8707",
        "file": "pdfs/issue8707.pdf",
        "md5": "d3dc670adde9ec9fb82c974027033029",