message: Only perform the zero-sized type shortcut in ValueObject::Update for Swift.
  In C++ even empty structs have a size of at least 1.
  rdar://problem/51815632
diff: @@ -130,9 +130,11 @@ bool ValueObjectVariable::UpdateValue() {
  m_error.Clear();
  Variable *variable = m_variable_sp.get();
  - // Check if the type has size 0. If so, there is nothing to update.
  + // Check if the type has size 0. If so, there is nothing to update,
  + // unless the type is C++ where even empty structs have a non-zero
  + // size.
  CompilerType var_type(GetCompilerTypeImpl());
  - if (var_type.IsValid()) {
  + if (var_type.IsValid() && var_type.GetMinimumLanguage() == lldb::eLanguageTypeSwift) {
  ExecutionContext exe_ctx(GetExecutionContextRef());
  llvm::Optional<uint64_t> size =
  var_type.GetByteSize(exe_ctx.GetBestExecutionContextScope());
  