[Compiler-sig] current status of ast branch

[Jeremy Hylton]

I've been slowly fixing failed tests.  It's down to 14 failures when
running the basic test suite.  A number of these look easy -- syntax
errors that newcompile.c doesn't raise.  Some of the failures involve
line numbers, which should be easy to fix but has proved tricky so far.

14 tests failed:
    test_builtin test_difflib test_eof test_generators test_global
    test_grammar test_importhooks test_inspect test_pep263
    test_profile test_repr test_scope test_symtable test_trace

The memory consumption is a lot better.  Simply freeing the asts after
they are compiled makes a big difference <wink>.

Jeremy