The symbol table pass didn't have an explicit case for the list_iter
node which is used only for a nested list comprehension.  As a result,
the target of the list comprehension was treated as a use instead of
an assignment.  Fix is to add a case to symtable_node() to handle
list_iter.

Also, rework and document a couple of the subtler implementation
issues in the symbol table pass.  The symtable_node() switch statement
depends on falling through the last several cases, in order to handle
some of the more complicated nodes like atom.  Add a comment
explaining the behavior before the first fall through case.  Add a
comment /* fall through */ at the end of case so that it is explicitly
marked as such.

Move the for_stmt case out of the fall through logic, which simplifies
both for_stmt and default.  (The default used the local variable start
to skip the first three nodes of a for_stmt when it fell through.)

Rename the flag argument to symtable_assign() to def_flag and add a
comment explaining its use:

   The third argument to symatble_assign() is a flag to be passed to
   symtable_add_def() if it is eventually called.  The flag is useful
   to specify the particular type of assignment that should be
   recorded, e.g. an assignment caused by import.

The fix is a band-aid: type_call() now makes the same exception for a
single-argument call to type() as type_new() was already making.

to link a C++ main using the C++ compiler. Fixes #472007.

isinstance() now allows any object as the first argument and a class, a
type or something with a __bases__ tuple attribute for the second
argument.  This closes SF patch #464992.

(The rest of the test cases are trivial, so I don't feel too bad.)

Quoth the OpenSSL RAND_add man page:

    OpenSSL makes sure that the PRNG state is unique for each
    thread. On systems that provide /dev/urandom, the
    randomness device is used to seed the PRNG transparently.
    However, on all other systems, the application is
    responsible for seeding the PRNG by calling RAND_add(),
    RAND_egd(3) or RAND_load_file(3).

I decided to expose RAND_add() because it's general and RAND_egd()
because it's a useful special case.  RAND_load_file() didn't seem to
offer much over RAND_add(), so I skipped it.  Also supplied
RAND_status() which returns true if the PRNG is seeded and false if
not.

closes patch 470254

    test_no_semis_header_splitter(): This actually should still split.

    test_no_split_long_header(): An example of an unsplittable line.

    test_no_semis_header_splitter(): Test for SF bug # 471918, Generator
    splitting long headers.

    _split_header(): Split on folding whitespace if the attempt to split
    on semi-colons failed.

    _split_header(): Patch by Matthew Cowles for fixing SF bug # 471918,
    Generator splitting long headers.

PyType_HasFeature(t, Py_TPFLAGS_HAVE_CLASS).

ValueError on too-large inputs.

and fixup_slot_dispatchers() always select the proper slot dispatcher.
This affects slot_sq_item(), slot_tp_getattro(), and
slot_tp_getattr_hook().

There are now no known cases where the compiler package computes a
stack depth lower than the one computed by the builtin compiler.  (To
achieve this state, we had to fix bugs in both compilers :-).

The chief change is to do the depth calculations with respect to basic
blocks.  The stack effect of block is calculated.  Then the flow graph
is traversed using breadth-first search to find the max weight path
through the graph.

Had to fix the StackDepthTracker to calculate the right info for
several opcodes: LOAD_ATTR, CALL_FUNCTION (and friends), MAKE_CLOSURE,
and DUP_TOPX.

XXX Still need to handle free variables in MAKE_CLOSURE.

XXX There are still a lot of places where the computed stack depth is
larger than for the builtin compiler.  These won't cause the
interpreter to overflow the frame, but they waste space.

Also minor tweaks to internal routines.
Use PyCF_MASK instead of explicit list of flags.

For the MAKE_CLOSURE opcode, the number of items popped off the stack
depends on both the oparg and the number of free variables for the
code object.  Fix the code so it accounts for the free variables.

In com_classdef(), record an extra pop to account for the STORE call
after the BUILD_CLASS.

Get rid of some commented out debugging code in com_push() and
com_pop().

Factor string resize logic into helper routine com_check_size().

In com_addbyte(), remove redudant if statement after assert.  (They
test the same condition.)

In several routines, use string macros instead of string functions.

d_type before calling the wrapped function.

fixup_slot_dispatchers(): fix indentation.

- replace some log_error() calls with log_message()

- flush self.rfile before forking too (hope this works on Windows)

Add --install-scripts=$(BINDIR) argument to "setup.py install"
invocation.

line fits in reasonable screen width.

Made the presence/absence of a semicolon after macros consistent.

removed the tricks).

Changed the ENTER/LEAVE_ZLIB macros so as not to create a new block (a
new block is neither necessary nor helpful).