ASSERTION FAILED: watchpoints (./runtime/ScopedArgumentsTable.cpp(130))

rdar://121446658
https://bugs.webkit.org/show_bug.cgi?id=267946

Reviewed by Alexey Shvayka.

Insatead of using an ASSERT that we have a valid WatchpointSet in ScopedArgumentsTable::trySetWatchpointSet(), we can just
exit early if the passed in WatchpointSet is null.  This can happen if the JIT is not enabled.

Updated the test to run both with and wothout the JIT.

* JSTests/stress/arrow-function-captured-arguments-aliased.js:
* Source/JavaScriptCore/runtime/ScopedArgumentsTable.cpp:
(JSC::ScopedArgumentsTable::trySetWatchpointSet):

Originally-landed-as: 272448.339@safari-7618-branch (66df5c6). rdar://124555300
Canonical link: https://commits.webkit.org/276598@main

JSTests/stress/arrow-function-captured-arguments-aliased.js

@@ -1,3 +1,6 @@
+//@ runDefault
+//@ runNoJIT
+
 function createOptAll(count) {
     count = 0;
 

Source/JavaScriptCore/runtime/ScopedArgumentsTable.cpp

@@ -127,7 +127,9 @@ ScopedArgumentsTable* ScopedArgumentsTable::trySet(VM& vm, uint32_t i, ScopeOffs
 
 void ScopedArgumentsTable::trySetWatchpointSet(uint32_t i, WatchpointSet* watchpoints)
 {
-    ASSERT(watchpoints);
+    if (!watchpoints)
+        return;
+
     if (i >= m_watchpointSets.size())
         return;