It's a little bit complicated due to the fact that
gdb has to be the parent so that it can have the permissions
to ptrace the process that segfaults.

imports apparently have to look at the globals scope in order
to determine how to handle relative imports and package references.

Sqlalchemy for some reason does this, and once we have this sqlalchemy
imports.

delete capi/float.cpp

I don't remember the original reasoning for having the separate capi/float.cpp,
and all the other runtime/ files have their CAPI methods inline.

workaround for __rdtscp for now

put back in the Timer-based stats I removed in the stats-timer branch…

put back in the Timer-based stats I removed in the stats-timer branch, and allow stat timers to be disabled separately from the rest of the stats (disable them by default.)

Stat timers

Each thread has a stack of timers (which should have automatic scope.)  pushing a timer
onto the stack pauses the currently running one to avoid double counting, and popping a
timer resumes the previous one.

also make sure we pause the current timer, and swap out the current stack of timers when
swapping to/from generator stacks, since otherwise pushes/pops won't line up and we hit
asserts in StatTimer.

Timers and StatTimers accumulate their durations in terms of CPU ticks, which are converted
to microseconds only at Stats::dump() time, calculated with our estimate of CPU frequency.
Needless to say, this only works when there is no CPU stepping/scaling.

There are some additions to the Timer class that allow us to get the start/end time so that
we can sync up StatTimers with them, if both are used in a given piece of code.

getCPUTicks() is only implemented using __rdtscp() at the moment, so won't work on anything
not recent relatively recent x86.

we accumulate total ticks during dumping and output both 'ticks_in_main' and 'ticks_all_timers',
which should be equal.

These happen if you never have run the makefile build,
which should become increasingly common.

I didn't bother testing that this doesn't break the makefile build.

fix the remaining subclass checks for list comparisons <, <=, >, >=

Reduce memory by not caching analysis passes

On the simple test of `pyston -c "import pip"`, it reduces memory
usage from 194MB to 153MB (20% of the memory previously was cached
analysis data).  It also increases our benchmark geomean by ~1%,
which isn't great, but I think we can get that back eventually and
I don't think it's worth blocking this memory improvement for that.

I guess in CPython, __file__ will be the path to the pyc if that's how
the library was loaded.  (We don't do that but that difference isn't the
issue here.)  So that makes these tests, which print __file__, sensitive
to whether the last run of the test was through cpython (pyc exists and
__file__ ends in pyc) or through pyston (pyc exists but was wasn't valid
for cpython, and __file__ ends in py)

Just do some canonicalization when printing

- make heap dumping work again
- refactor some of the heap statistics to work in OOM scenarios
  (ie be able to not collect the ones that would require allocation to track)
- collect some hcls statistics as well
- print stats to stderr rather than stdout
  - I think this makes more sense since it is not really part of the program
    output; it also makes it more likely that "PYSTON_RUN_ARGS=s" will work

add support for assigning a generator to a list slice

add exception_hierarchy.txt which test/cpython/test_pep352.txt needs

rename member -> member_descriptor

minor tester & test fixes for python microrevision compatibility

Conflicts:
	src/runtime/float.cpp

list __eq__ and __ne__ work for rhs's that are list subclasses

prohibit _PyTuple_Resize for objects that are subclasses of tuple

implement `real` and `imag` for `int`, `long`, and `float`

ignore untracked files in the gflags submodule

remove ununsed class BoxedUnicode

Add PyGC_AddRoot calls any time we assign to a static variable

It seems like there's only one potentially bad one (zip_directory_cache),
and the rest are more or less benign (most of the occurrences are added
to the module as well as attributes), but it's probably good practice.