part 3 - Implement special handling for operators using U+0338 and U+…

…20D2.

MathML Core specifies that operators containing a UTF-16 strings of
length 2 ending with U+0338 COMBINING LONG SOLIDUS OVERLAY or U+20D2
COMBINING LONG VERTICAL LINE OVERLAY should just use the properties of
the first character. This commit implements that behavior. It removes
obsolete entries that are superseded by this rule and modifies
updateOperatorDictionary.pl to ensure that no such entries are present.

Existing WPT test operator-dictionary-combining.html is already passing
after bug 1789583 because the operators tested use the default spacing.
So extend it to try operators with different spacing.

[1] https://w3c.github.io/mathml-core/#dfn-algorithm-to-determine-the-category-of-an-operator

Differential Revision: https://phabricator.services.mozilla.com/D157707

bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1790009
gecko-commit: 35725e846f2e211e3c4b691fd6d33f5d5a1aa715
gecko-reviewers: emilio

mathml/presentation-markup/operators/operator-dictionary-combining.html

@@ -33,7 +33,12 @@
       var epsilon = 1;
       var emToPx = 25;
 
-      ["equal", "vertical_bar"].forEach(id => {
+      [
+          "equal",
+          "vertical_bar",
+          "left_normal_factor_semidirect_product",
+          "there_exists",
+      ].forEach(id => {
           var div = document.getElementById(id);
           var ref = div.getElementsByClassName("reference")[0];
           var totalSpaceRef = spaceBetween(ref, 0, 2);
@@ -104,5 +109,51 @@
       </math>
     </p>
   </div>
+  <div id="left_normal_factor_semidirect_product">
+    <p>
+      <math class="reference">
+        <mn>&nbsp;</mn>
+        <mo stretchy="false">⋉</mo>
+        <mn>&nbsp;</mn>
+      </math>
+    </p>
+    <p>
+      <math class="combining">
+        <mn>&nbsp;</mn>
+        <mo stretchy="false">⋉&#x338;</mo>
+        <mn>&nbsp;</mn>
+      </math>
+    </p>
+    <p>
+      <math class="combining">
+        <mn>&nbsp;</mn>
+        <mo stretchy="false">⋉&#x20D2;</mo>
+        <mn>&nbsp;</mn>
+      </math>
+    </p>
+  </div>
+  <div id="there_exists">
+    <p>
+      <math class="reference">
+        <mn>&nbsp;</mn>
+        <mo stretchy="false">∃</mo>
+        <mn>&nbsp;</mn>
+      </math>
+    </p>
+    <p>
+      <math class="combining">
+        <mn>&nbsp;</mn>
+        <mo stretchy="false">∃&#x338;</mo>
+        <mn>&nbsp;</mn>
+      </math>
+    </p>
+    <p>
+      <math class="combining">
+        <mn>&nbsp;</mn>
+        <mo stretchy="false">∃&#x20D2;</mo>
+        <mn>&nbsp;</mn>
+      </math>
+    </p>
+  </div>
 </body>
 </html>