gcc/libstdc++-v3/testsuite

We're in the process of converting the existing testsuite machinery to
use the new style DejaGnu framework.  Eventually, we'll abandon
../mkcheck.in in favor of this new testsuite framework.  

  Basically, a testcase contains dg-keywords (see dg.exp) indicating
what to do and what kinds of behaviour are to be expected.  New
testcases should be written with the new style DejaGnu framework in mind.

  The V3 testing framework supports additional keywords for the purpose
of easing the job of writing testcases.  All V3-keywords are of the
form @xxx@.  Currently supported keywords include:

  @require@ <files>
      The existence of <files> is essential for the test to complete
      successfully.  For example, a testcase foo.C using bar.baz as
      input file could say
	    // @require@ bar.baz
      The special variable % stands for the rootname, e.g. the
      file-name without its `.C' extension.  Example of use (taken
      verbatim from 27_io/filebuf.cc)
	   // @require@ %-*.tst %-*.txt

  @diff@ <first-list> <second-list>
      After the testcase compiles and ran successfully, diff
      <first-list> against <second-list>, these lists should have the
      same length.  The test fails if diff returns non-zero a pair of
      files.

-- Gaby