[lldb] Make Thread::WillResume() report whether it pushed a ThreadPlanStepOverBreakpoint

We'll need this later to determine whether we need to account for
the newly-pushed `ThreadPlanStepOverBreakpoint`.

Author: rocallahan

lldb/include/lldb/Target/Thread.h

@@ -200,11 +200,14 @@ class Thread : public std::enable_shared_from_this<Thread>,
   ///    The User resume state for this thread.
   lldb::StateType GetResumeState() const { return m_resume_state; }
 
-  // This function is called on all the threads before "ShouldResume" and
-  // "WillResume" in case a thread needs to change its state before the
-  // ThreadList polls all the threads to figure out which ones actually will
-  // get to run and how.
-  void SetupForResume();
+  /// This function is called on all the threads before "ShouldResume" and
+  /// "WillResume" in case a thread needs to change its state before the
+  /// ThreadList polls all the threads to figure out which ones actually will
+  /// get to run and how.
+  ///
+  /// \return
+  ///    True if we pushed a ThreadPlanStepOverBreakpoint
+  bool SetupForResume();
 
   // Do not override this function, it is for thread plan logic only
   bool ShouldResume(lldb::StateType resume_state);

lldb/source/Target/Thread.cpp

@@ -617,15 +617,15 @@ void Thread::WillStop() {
   current_plan->WillStop();
 }
 
-void Thread::SetupForResume() {
+bool Thread::SetupForResume() {
   if (GetResumeState() != eStateSuspended) {
     // First check whether this thread is going to "actually" resume at all.
     // For instance, if we're stepping from one level to the next of an
     // virtual inlined call stack, we just change the inlined call stack index
     // without actually running this thread.  In that case, for this thread we
     // shouldn't push a step over breakpoint plan or do that work.
     if (GetCurrentPlan()->IsVirtualStep())
-      return;
+      return false;
 
     // If we're at a breakpoint push the step-over breakpoint plan.  Do this
     // before telling the current plan it will resume, since we might change
@@ -663,11 +663,13 @@ void Thread::SetupForResume() {
               step_bp_plan->SetAutoContinue(true);
             }
             QueueThreadPlan(step_bp_plan_sp, false);
+            return true;
           }
         }
       }
     }
   }
+  return false;
 }
 
 bool Thread::ShouldResume(StateType resume_state) {