testsuite for primitive bound checking

(Patch by Pierre Chambart)

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14555 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Fix caml_string_{get,set}{16,32,64} bound checking in cmmgen

(Patch by Pierre Chambart)

Followup for trunk@14267:
  bound checking bug with caml_string_{get,set}{16,32,64}: fix the runtime C code

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14556 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02