[debug] test that functions optimize without breakpoints.

This came up in the context of a Twitter discussion, see this particular
tweet https://twitter.com/hashseed/status/905684048382754817 and the
relevant thread.

Change-Id: If2447169df999b64ce701a44321d48ba1bff2a06
Reviewed-on: https://chromium-review.googlesource.com/654598Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47864}

test/debugger/debug/debug-compile-optimized.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --opt
+// Flags: --opt --no-always-opt
 
 Debug = debug.Debug;
 
@@ -15,4 +15,17 @@ f();
 f();
 assertOptimized(f);
 
+var bp = Debug.setBreakPoint(f);
+assertUnoptimized(f);
+f();
+f();
+%OptimizeFunctionOnNextCall(f);
+f();
+assertUnoptimized(f);
+
+Debug.clearBreakPoint(bp);
+%OptimizeFunctionOnNextCall(f);
+f();
+assertOptimized(f);
+
 Debug.setListener(null);