PR libstdc++/79190 add fallback aligned_alloc implementation

PR libstdc++/79190 add fallback aligned_alloc implementation

libstdc++-v3:

	PR libstdc++/79190
	* libsupc++/del_opa.cc (operator delete(void*, std::align_val_t))
	[!_GLIBCXX_HAVE_ALIGNED_ALLOC && !_GLIBCXX_HAVE_POSIX_MEMALIGN
	&& !_GLIBCXX_HAVE_MEMALIGN && !_GLIBCXX_HAVE__ALIGNED_MALLOC]:
	Retrieve original pointer value allocated by malloc.
	* libsupc++/new_opa.cc [!_GLIBCXX_HAVE_ALIGNED_ALLOC
	&& !_GLIBCXX_HAVE_POSIX_MEMALIGN && !_GLIBCXX_HAVE_MEMALIGN
	&& !_GLIBCXX_HAVE__ALIGNED_MALLOC] (aligned_alloc(size_t, size_t)):
	Define, adjusting pointer value allocated by malloc and storing for
	retrieval by operator delete.

gcc/testsuite:

	PR libstdc++/79190
	* g++.dg/cpp1z/aligned-new3.C: Replace operator new so behaviour
	matches replaced operator delete.

From-SVN: r244933