[interpreter, debugger] fix remaining cctest failures.

test/cctest/test-debug.cc

Index: test/cctest/test-debug.cc
diff --git a/test/cctest/test-debug.cc b/test/cctest/test-debug.cc
index 2f7a05d214822b1c3e515cb965ae7ed1428d215c..c1cfc4ac799dcef15bb531f31626060ddb121acb 100644
--- a/test/cctest/test-debug.cc
+++ b/test/cctest/test-debug.cc
@@ -3458,26 +3458,25 @@ TEST(DebugConditional) {
   v8::Local<v8::Context> context = env.context();
   // Create a function for testing stepping. Run it to allow it to get
   // optimized.
-  const char* src = "function foo(x) { "
-                    "  var a;"
-                    "  a = x ? 1 : 2;"
-                    "  return a;"
-                    "}"
-                    "foo()";
+  const char* src =
+      "function foo(x) { "
+      "  return x ? 1 : 2;"

[vogelheim, 2016/03/15 09:51:51]

Hmm. Not sure, but this might count as cheating... ;-)

This new test case tests exactly what the old one was *meant* to test, so it's
arguably an improvement. But the old test case (accidentally) triggered a
difference in FCG and Ignition breakpoints (via an unrelated optimization in
Ignition), which is valuable in its own right.

Since we've come to the conclusion that this difference is intended (or at least
best we can do for now), I think ideally I'd want a test case that "documents"
this. E.g., the old test case, but with something like:
  CHECK_IMPLIES(FLAG_ignition, 2 == breakpoint_hit_count);
  CHECK_IMPLIES(!FLAG_ignition, 3 == breakpoint_hit_count);


I'm not entirely sure either way, so.. your choice! :)

[Yang, 2016/03/15 10:00:12]

The old version tested both a conditional, and the assignment-and-return combo.
Now It only tests the conditional, and the newly introduced
src/ignition/elided-instruction* tests test the assignment-and-return combo, so
I think we are not losing any test coverage here :)

+      "}"
+      "foo()";
   v8::Local<v8::Function> foo = CompileFunction(&env, src, "foo");
   SetBreakPoint(foo, 0);  // "var a;"
 
   step_action = StepIn;
   break_point_hit_count = 0;
   foo->Call(context, env->Global(), 0, NULL).ToLocalChecked();
-  CHECK_EQ(3, break_point_hit_count);
+  CHECK_EQ(2, break_point_hit_count);
 
   step_action = StepIn;
   break_point_hit_count = 0;
   const int argc = 1;
   v8::Local<v8::Value> argv_true[argc] = {v8::True(isolate)};
   foo->Call(context, env->Global(), argc, argv_true).ToLocalChecked();
-  CHECK_EQ(3, break_point_hit_count);
+  CHECK_EQ(2, break_point_hit_count);
 
   // Get rid of the debug event listener.
   v8::Debug::SetDebugEventListener(isolate, nullptr);