2018-06-11  Olivier Hainque  <hainque@adacore.com>

        * dwarf2out.c (gen_compile_unit_die): Fallout to DW_LANG_Ada83
        for Ada with strict dwarf2.

	testsuite/

        * gnat.dg/lang-dw2.adb: New test.
        * gnat.dg/lang-dw3.adb: New test.

From-SVN: r261432