Double counted copy-prop syms hit FailFast

- copy prop'd syms can be referenced by key and value
- both key and value can be in the unrestorableSymbols list
- When restoring from the value remove the key from the list also
- Also check whether needed based on the value's liveness not key

lib/Backend/LinearScan.cpp

@@ -5135,8 +5135,10 @@ void LinearScan::GeneratorBailIn::BuildBailInSymbolList(
 
         if (unrestorableSymbols.TestAndClear(value->m_id))
         {
-            if (this->NeedsReloadingSymWhenBailingIn(copyPropSym.Key()))
+            if (this->NeedsReloadingSymWhenBailingIn(copyPropSym.Value()))
             {
+                // we're restoring this sym based on the value also remove the key from unrestorableSymbols
+                unrestorableSymbols.Clear(key->m_id);
                 BailInSymbol bailInSym(key->m_id /* fromByteCodeRegSlot */, value->m_id /* toBackendId */);
                 bailInSymbols->PrependNode(this->func->m_alloc, bailInSym);
             }

test/es6/async-jit-bugs.js

@@ -0,0 +1,33 @@
+//-------------------------------------------------------------------------------------------------------
+// Copyright (C) Microsoft. All rights reserved.
+// Copyright (c) 2021 ChakraCore Project Contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
+//-------------------------------------------------------------------------------------------------------
+
+function main() {
+    const v2 = [13.37,13.37,13.37,13.37,13.37];
+    async function v4(v5,v6,v7,v8) {
+        const v10 = 0;
+        for (let v14 = 0; v14 < 8; v14++) {
+            v5["vEBD7ei78q"] = v14;
+        }
+        for (let v16 = 1; v16 < 1337; v16++) {
+            const v17 = v2.__proto__;
+            const v23 = [13.37,13.37,-2.2250738585072014e-308,13.37,13.37];
+            const v24 = v23.length;
+            const v25 = "-4294967296";
+            const v26 = 7;
+            function* v28(v29,v30,v31,...v32) {}
+            let v33 = -2.2250738585072014e-308;
+            const v34 = v28(v33,Object,Object);
+            const v35 = 13.37;
+            const v36 = 2384357829;
+            const v37 = await "-4294967296";
+            const v38 = --v33;
+        }
+        const v39 = 128;
+        print("pass")
+    }
+v4("vEBD7ei78q");
+}
+main();

test/es6/generator-jit-bugs.js

@@ -4,8 +4,9 @@
 // Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
 //-------------------------------------------------------------------------------------------------------
 
-let results = 0;
-let test = 0;
+// Simpler mini-test harness to avoid any complicating factors when testing these jit bugs
+var results = 0;
+var test = 0;
 const verbose = WScript.Arguments[0] != "summary";
 
 function check(actual, expected) {
@@ -90,6 +91,7 @@ check(gen4.next().value, 1);
 check(gen4.next().value, 2);
 check(gen4.next().value, 3);
 
+// Test 5 - scope slots fail to load inside for-in loop
 title("Load Scope Slots in presence of for-in");
 function* gf5(v1) {
     for(v0 in v1) {
@@ -106,6 +108,7 @@ check(gen5.next().value, undefined);
 check(gen5.next().value, undefined);
 check(gen5.next().value, undefined);
 
+// Test 6 - scope slots used in loop control have invalid values
 title("Load Scope Slots used in loop control");
 function* gf6 () {
     for (let v1 = 0; v1 < 1000; ++v1) {
@@ -121,6 +124,7 @@ check(gen6.next().value, 1);
 check(gen6.next().value, 2);
 check(gen6.next().value, 3);
 
+// Test 7 - storing scoped slot from loop control in array 
 title("Load Scope Slots used in loop control and captured indirectly");
 function* gf7(v1) {
     for (const v2 in v1) {
@@ -136,5 +140,17 @@ check(gen7.next().value, 1);
 check(gen7.next().value, 2);
 check(gen7.next().value, undefined);
 
+// Test 8 - copy prop'd sym is counted as two values - hits bookkeeping FailFast 
+title("Copy prop sym double counted in unrestorable symbols hits FailFast");
+function* gf8() {
+    var v8 = 1.1;
+    yield* [];
+    yield {v8};
+}
+
+check(gf8().next().value.v8, 1.1);
+check(gf8().next().value.v8, 1.1);
+check(gf8().next().value.v8, 1.1);
+
 
 print("pass");

test/es6/rlexe.xml

@@ -153,6 +153,27 @@
       <tags>exclude_nonative, exclude_dynapogo</tags>
     </default>
   </test>
+  <test>
+    <default>
+      <files>async-jit-bugs.js</files>
+      <compile-flags>-JitES6Generators -args summary -endargs</compile-flags>
+      <tags>exclude_nonative</tags>
+    </default>
+  </test>
+  <test>
+    <default>
+      <files>async-jit-bugs.js</files>
+      <compile-flags>-JitES6Generators -off:simplejit -args summary -endargs</compile-flags>
+      <tags>exclude_nonative</tags>
+    </default>
+  </test>
+  <test>
+    <default>
+      <files>async-jit-bugs.js</files>
+      <compile-flags>-JitES6Generators -off:fulljit -args summary -endargs</compile-flags>
+      <tags>exclude_nonative, exclude_dynapogo</tags>
+    </default>
+  </test>
   <test>
     <default>
       <files>proto_basic.js</files>