Fix ECMA 262 \Z and \z tests

The old test was incorrect because "\Z" is actually valid. It matches a
literal Z in ECMA 262.

Author: ssilverman

tests/draft2019-09/optional/ecmascript-regex.json

@@ -1,11 +1,29 @@
 [
     {
         "description": "ECMA 262 regex non-compliance",
-        "schema": { "format": "regex" },
+        "schema": {
+            "type": "string",
+            "pattern": "^\\S\\Z"
+        },
         "tests": [
             {
-                "description": "ECMA 262 has no support for \\Z anchor from .NET",
-                "data": "^\\S(|(.|\\n)*\\S)\\Z",
+                "description": "\\Z should match literal Z",
+                "data": "xZ",
+                "valid": true
+            },
+            {
+                "description": "\\Z should not match end",
+                "data": "x",
+                "valid": false
+            },
+            {
+                "description": "\\z should match literal z",
+                "data": "xz",
+                "valid": true
+            },
+            {
+                "description": "\\z should not match end",
+                "data": "x",
                 "valid": false
             }
         ]