[test] Make a few tests robust to GC stress

A recent unrelated change caused these tests to get unlucky in
GC stress mode. Their "assertOptimized" expectations rely on
certain type feedback data not getting flushed at the wrong time.

Bug: v8:10846
Change-Id: I86d0b0c049539e4a69aa764cc6ec92465ca12beb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2381458Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Auto-Submit: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69617}

test/mjsunit/check-bounds-array-index.js

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 //
 // Flags: --allow-natives-syntax --opt --no-always-opt
+// Flags: --no-stress-flush-bytecode
 
 let arr = [1, 2, 3];
 

test/mjsunit/check-bounds-string-from-char-code-at.js

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 //
 // Flags: --allow-natives-syntax --opt --no-always-opt
+// Flags: --no-stress-flush-bytecode
 
 let string = "foobar";
 

test/mjsunit/constant-folding-2.js

@@ -27,6 +27,7 @@
 
 
 // Flags: --allow-natives-syntax --nostress-opt --opt
+// Flags: --no-stress-flush-bytecode
 
 function test(f, iterations) {
   %PrepareFunctionForOptimization(f);

test/mjsunit/mjsunit.status

@@ -255,6 +255,7 @@
   'regress/regress-crbug-137689': [SKIP],
   'regress/regress-trap-allocation-memento': [SKIP],
   'regress/regress-2249': [SKIP],
+  'regress/regress-3709': [SKIP],
   'regress/regress-4121': [SKIP],
   'regress/regress-6989': [SKIP],
   'compare-known-objects-slow': [SKIP],

test/mjsunit/regress/regress-1034449.js

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 // Flags: --allow-natives-syntax --opt --no-always-opt
+// Flags: --no-stress-flush-bytecode
 
 function f(len) {
   return new Array(len);