Don't try to optimize an already-optimized function

Bug: chromium:1028208
Change-Id: I439cb5acf4487ab0e4af0dcd065f1ccb78b2e7a1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1946351Reviewed-by: Mythri Alle <mythria@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65282}

src/execution/runtime-profiler.cc

@@ -172,6 +172,7 @@ bool RuntimeProfiler::MaybeOSR(JSFunction function, InterpretedFrame* frame) {
 
 OptimizationReason RuntimeProfiler::ShouldOptimize(JSFunction function,
                                                    BytecodeArray bytecode) {
+  if (function.IsOptimized()) return OptimizationReason::kDoNotOptimize;
   int ticks = function.feedback_vector().profiler_ticks();
   int ticks_for_optimization =
       kProfilerTicksBeforeOptimization +

test/mjsunit/compiler/regress-1028208.js

+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --no-use-ic --interrupt-budget=100 --always-osr
+
+const num_iterations = 1000;
+let i = 0;
+const re = /foo.bar/;
+const RegExpPrototypeExec = RegExp.prototype.exec;
+re.exec = function gaga(str) {
+    return (i++ < num_iterations) ? RegExpPrototypeExec.call(re, str) : null;
+};
+re.__defineGetter__("global", () => true);
+"foo*bar".match(re);