Yet Another Attempt to fix test on xplat

test/Regex/Bug15992535-xplat.baseline

@@ -0,0 +1 @@
+

test/Regex/rlexe.xml

@@ -221,11 +221,19 @@
   <test>
     <default>
       <files>Bug15992535.js</files>
-      <!-- Test should fail assertion in debug build, so do not run -->
-      <tags>exclude_chk</tags>
-      <!-- We need an empty baseline to convince the test system
-           that the test is successful even though it fails-fast. -->
+      <!-- Test should fail assertion in debug build, so do not run. -->
+      <tags>exclude_chk,exclude_xplat</tags>
       <baseline>Bug15992535.baseline</baseline>
     </default>
   </test>
+  <!-- Mac/Linux variant of above test, which expects the additional
+       newline generated by the fail-fast on those platforms. -->
+  <test>
+    <default>
+      <files>Bug15992535.js</files>
+      <!-- Test should fail assertion in debug build, so do not run. -->
+      <tags>exclude_chk,exclude_win7,exclude_win8,exclude_winBlue,exclude_win10</tags>
+      <baseline>Bug15992535-xplat.baseline</baseline>
+    </default>
+  </test>
 </regress-exe>