Merge branch 'jc/qsort-s-alignment-fix'

Fix a hand-rolled alloca() imitation that may have violated
alignment requirement of data being sorted in compatibility
implementation of qsort_s() and stable qsort().

* jc/qsort-s-alignment-fix:
  stable-qsort: avoid using potentially unaligned access
  compat/qsort_s.c: avoid using potentially unaligned access