shouldfail'ing sourcelocation

   How exactly can we shouldfail the sourcelocation test on those
platforms like darwin which don't support dwarf4...

   To make this test pass, one need to have up-to-date addr2line installed
   to parse the dwarf4 data format.

I see the comments...

#
# Run the test specified by srcfile and resultfile. compile_args and
# exec_args are options telling this proc how to work.
#   `no-link'     don't try to link the program
#   `no-exec'     don't try to run the test
#   `xfail-gcj'   compilation from source will fail
#   `xfail-javac' compilation with javac will fail
#   `xfail-gcjC'  compilation with gcj -C will fail
#   `shouldfail'  compilation from source is supposed to fail
#                 This is different from xfail, which marks a known
#                 failure that we just haven't fixed.
#                 A compilation marked this way should fail with any
#                 front end.
#   `xfail-byte'  compilation from bytecode will fail
#   `xfail-exec'  exec will fail
#   `xfail-output'
#                 output will be wrong
#   `xfail-byte-output'
#                 output will be wrong when compiled from bytecode
#   `xfail-source-output'
#                 output will be wrong when compiled from source code
#   `need-threads'
#                 test relies on thread support
#

in libjava/testsuite/lib/libjava.exp but no evidence of these being used
on any particular test for specified targets in the libjava testsuite.
Thanks in advance for any advice here.
          Jack