[debugger] Re-enable --always-opt in one debugger test.

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 e58bca662245a15e70af0223425eaf0a1fd3daf8..e1e928f43a9f4785dc37d3f03329e301cec2b1a1 100644
--- a/test/cctest/test-debug.cc
+++ b/test/cctest/test-debug.cc
@@ -6706,10 +6706,6 @@ TEST(Backtrace) {
 
   v8::Debug::SetMessageHandler(BacktraceData::MessageHandler);
 
-  // TODO(mstarzinger): This doesn't work with --always-opt because we don't
-  // have correct source positions in optimized code. Enable once we have.
-  i::FLAG_always_opt = false;
-
   const int kBufferSize = 1000;
   uint16_t buffer[kBufferSize];
   const char* scripts_command =