review of graphite testsuite patch

[Janis Johnson]

This review of the testsuite changes for graphite is based on

  http://cri.ensmp.fr/people/pop/gcc/1142_testsuite.diff

The tests all use -fdump-tree-graphite-all and then look at and
remove only the dump file with "graphite" in the name.  Is there a
different dump option to get just that one file?  If not and there are
additional dump files generated, make sure they are also cleaned up.

Procedure scan-graphite-dump-times looks for "Graphite loop
optimizations cannot be used"; would that message be given only for
particular code, or for any compilation by a particular compiler?
If the latter then there should instead be a new effective-target
keyword "graphite", enabled by adding check_effective_target_graphite
in target-supports.exp similar to the other procedures in that file.
The whole directory of tests could be skipped by having graphite.exp
return early if "graphite" is not true.  This would also mean that
the graphite tests can use scan-tree-dump-files instead of a special
scan procedure.

If scan-graphite-dump-times is needed then it should support XFAIL
and a target list, like the other scan functions.  See scan-dump in
scandump.exp for how this is done.

All of the tests use "dg-do compile".  You could set dg-do-what-default
to "compile" and not need to use dg-do within the tests.  This is just
a suggestion.

Almost all tests use the same options.  Within the graphite.exp files
in the test suites you could set GRAPHITE_FLAGS to the options that are
used for most tests and pass that, instead of DEFAULT_CFLAGS, to
dg-runtest.  Those could be overridden in individual tests.  Again,
this is just a suggestion.

Test gfortran.dg/graphite/scop-1.f doesn't do any checking, what is
its purpose?

Janis