[lldb] Replace default bodies of special member functions with = default;

Replace default bodies of special member functions with = default;

$ run-clang-tidy.py -header-filter='lldb' -checks='-*,modernize-use-equals-default' -fix ,

https://clang.llvm.org/extra/clang-tidy/checks/modernize-use-equals-default.html

Differential revision: https://reviews.llvm.org/D104041

lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptRuntime.cpp

@@ -61,7 +61,7 @@ namespace {
 template <typename type_t> class empirical_type {
 public:
   // Ctor. Contents is invalid when constructed.
-  empirical_type() {}
+  empirical_type() = default;
 
   // Return true and copy contents to out if valid, else return false.
   bool get(type_t &out) const {