these tests validate on win/xp.

  - if any issues with dos-style line-endings remain,
    please apply dos2unix for now, and let me know

  - ghci024 has ghci024.py instead of ghci024.stdout;
    the prepare024 function defined in there generates
    a platform- and version-specific ghci024.stdout
    for the test (see all.T)

  - ghci025 uses the (non-advertised) new -s option
    to get sorted :browse output for stable tests
    (to work around #1799). if this isn't sufficient,
    please set normal to ignore_output in all.T for
    now (until #1799 is fixed), and let me know

Revert to getting an error from the renamer

Suggested by Claus Reinke

pointed out by Claus Reinke

Allows us to use a different name base for foo.stderr for old compilers, e.g.
test('tc141',
     namebase_if_compiler_lt('ghc', '6.9', 'tc141-6.8'),
     compile_fail,
     [''])

* Code of #1776 from aslatter@gmail.com