[rebranch][lldb] Rename reference to ThreadPlan::DidPop

41d0b20 renamed `WillPop` to `DidPop`.
Rename the override in `ThreadPlanStepInAsync`.

Author: bnbarham

lldb/source/Plugins/LanguageRuntime/Swift/SwiftLanguageRuntimeNames.cpp

@@ -319,7 +319,7 @@ class ThreadPlanStepInAsync : public ThreadPlan {
 
   bool StopOthers() override { return false; }
 
-  void WillPop() override {
+  void DidPop() override {
     if (m_async_breakpoint_sp)
       m_async_breakpoint_sp->GetTarget().RemoveBreakpointByID(
           m_async_breakpoint_sp->GetID());