[LLDB] Applying clang-tidy modernize-use-equals-default over LLDB

Applied modernize-use-equals-default clang-tidy check over LLDB.

This check is already present in the lldb/.clang-tidy config.

Differential Revision: https://reviews.llvm.org/D121844

lldb/source/Core/IOHandlerCursesGUI.cpp

@@ -2282,7 +2282,7 @@ protected:
 
 class FormDelegate {
 public:
-  FormDelegate() {}
+  FormDelegate() = default;
 
   virtual ~FormDelegate() = default;
 
@@ -3644,7 +3644,7 @@ protected:
 
 class SearcherDelegate {
 public:
-  SearcherDelegate() {}
+  SearcherDelegate() = default;
 
   virtual ~SearcherDelegate() = default;