[MERGE #5343 @meg-gupta] Revert "Enable deadstore for jit loop bodies when there is try"

Merge pull request #5343 from meg-gupta:revertdeadstore

This reverts commit 1a9529a.

In SimpleJit there is no accurate from try block to finally block, which can cause incorrect deadstores.

Author: Meghana Gupta

lib/Backend/BackwardPass.cpp

@@ -107,7 +107,9 @@ BackwardPass::DoMarkTempObjectVerify() const
 bool
 BackwardPass::DoDeadStore(Func* func)
 {
-    return !PHASE_OFF(Js::DeadStorePhase, func);
+    return
+        !PHASE_OFF(Js::DeadStorePhase, func) &&
+        (!func->HasTry() || func->DoOptimizeTry());
 }
 
 bool
@@ -122,7 +124,8 @@ bool
 BackwardPass::DoDeadStoreSlots() const
 {
     // only dead store fields if glob opt is on to generate the trackable fields bitvector
-    return (tag == Js::DeadStorePhase && this->func->DoGlobOpt());
+    return (tag == Js::DeadStorePhase && this->func->DoGlobOpt()
+        && (!this->func->HasTry()));
 }
 
 // Whether dead store is enabled for given func and sym.

test/EH/rlexe.xml

@@ -204,11 +204,4 @@
        <files>tfjitloopbug.js</files>
   </default>
   </test>
-  <test>
-    <default>
-      <files>tcdeadstorebug.js</files>
-      <compile-flags> -maxinterpretcount:1 -maxsimplejitruncount:1 -MinMemOpCount:0 -werexceptionsupport  -bgjit- -loopinterpretcount:1</compile-flags>
-      <tags>exclude_dynapogo</tags>
-    </default>
-  </test>
 </regress-exe>