Add missing stub <scoped_allocator>

Author: jeongsoolee09

cpp/common/test/includes/standard-library/scoped_allocator

@@ -0,0 +1 @@
+#include <scoped_allocator.h>

cpp/common/test/includes/standard-library/scoped_allocator.h

@@ -0,0 +1,35 @@
+#ifndef _GHLIBCPP_SCOPED_ALLOCATOR
+#define _GHLIBCPP_SCOPED_ALLOCATOR
+
+#include <cstddef>
+#include <memory>
+
+namespace std {
+
+// =============================================================================
+// std::scoped_allocator_adaptor
+// =============================================================================
+
+template <typename T1, typename... T2>
+class scoped_allocator_adaptor : public T1 {
+public:
+  using outer_allocator_type = T1;
+  using value_type = typename allocator_traits<T1>::value_type;
+  using size_type = typename allocator_traits<T1>::size_type;
+  using pointer = typename allocator_traits<T1>::pointer;
+  using const_void_pointer = typename allocator_traits<T1>::const_void_pointer;
+
+  scoped_allocator_adaptor();
+  scoped_allocator_adaptor(const scoped_allocator_adaptor &) noexcept;
+  scoped_allocator_adaptor(scoped_allocator_adaptor &&) noexcept;
+
+  ~scoped_allocator_adaptor() = default;
+
+  pointer allocate(size_type);
+  pointer allocate(size_type, const_void_pointer);
+  void deallocate(pointer, size_type);
+};
+
+} // namespace std
+
+#endif // _GHLIBCPP_SCOPED_ALLOCATOR