[debugger] account for inlined functions when stepping.

test/debugger/regress/regress-5901-1.js

Index: test/debugger/regress/regress-5901-1.js
diff --git a/test/debugger/regress/regress-5901-1.js b/test/debugger/regress/regress-5901-1.js
new file mode 100644
index 0000000000000000000000000000000000000000..49becc9294f9c0be015d950ba6d56db6b1f536d7
--- /dev/null
+++ b/test/debugger/regress/regress-5901-1.js
@@ -0,0 +1,50 @@
+// Copyright 2017 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: --ignition --turbo
+
+function f() {
+  throw new Error();
+}
+
+function g() {
+  try {
+    f();
+  } catch (e) {
+    return 1;  // Break
+  }
+}
+
+function h() {
+  return g();
+}
+
+h();
+h();
+
+var Debug = debug.Debug;
+var step_count = 0;
+var exception = null;
+
+function listener(event, exec_state, event_data, data) {
+  if (event == Debug.DebugEvent.Exception) {
+    step_count++;
+    exec_state.prepareStep(Debug.StepAction.StepNext);
+  } else if (event == Debug.DebugEvent.Break) {
+    step_count++;
+    try {
+      assertTrue(exec_state.frame().sourceLineText().includes('Break'));
+    } catch (e) {
+      exception = e;
+      print(e);
+    }
+  }
+}
+
+Debug.setListener(listener);
+Debug.setBreakOnException();
+% OptimizeFunctionOnNextCall(h);
+h();
+Debug.setListener(null);
+assertNull(exception);