20_util/memory_resource/2.cc FAILs on AIX 7.2.0.0, because aligned_alloc
incorrectly requires the alignment to be a multiple of sizeof(void*).
This adds a workaround to the operator new overload taking an alignment
value, to increase the alignment (and size) if needed.
* libsupc++/new_opa.cc (operator new(size_t, align_val_t)): Add
workaround for aligned_alloc bug on AIX.
* testsuite/18_support/new_aligned.cc: New test.
From-SVN: r263073