make ocamlopt pretty-print uncaught exceptions just as ocamlc and Printexc


git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@13809 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
tweak tests/backtrace to also test ocamlopt

Note that native and byte-test share the same reference file, so in
particular they check that ocamlc and ocamlopt report uncaught
exception in the exact same way. Passing this test required a change
in asmrun/backtrace.c/print_location.


git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@13810 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
testsuite/tests/backtrace: no need to re-run backtrace2 which catches all exceptions


git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@13811 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
testsuite/tests/backtrace: new test to exercize Printexc.get_raw_backtrace


git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@13812 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02