Improve REPL support

This fixes a bug with expressions inside loops in interactive mode
that resulted in expressions not being printed:

    >> for i in range(3):
    ...    i
    ...
    >>

Python prints the value every iteration:

    >> for i in range(3):
    ...    i
    ...
    0
    1
    2
    >>>

The same also applies to while loops.

vregs: reuse block local vregs

user visible: used for all non compiler generated names, name could be used in a single block or multiple
              all frames contain atleast this vregs in order to do frame introspection
cross block : used for compiler generated names which get used in several blocks or which have closure scope
single block: used by compiler created names which are only used in a single block.
              get reused for different names

we assign the lowest numbers to the user visible ones, followed by the cross block ones and finally the single block
ones. we do this because not all tiers use all of the vregs and it still makes it fast to switch between tiers.

Fix some issues that crop up on 15.10

not very happy about this but it's better than having a flaky CI...

Some fixings that let scipy tests pass.

major bjit improvements

float.cpp: now that we have float.c use some of the functions directly

CPython has this check. I think Pyston missed it when switch to the
CPython way of handling some inheritance functionality.

References:
CPython code:
https://github.com/python/cpython/blob/2.7/Objects/typeobject.c#L4074
Pyston commit that switch to the CPython way of handling it:
https://github.com/dropbox/pyston/commit/251f417abd68c4b018217ae3b1901b3f1687384d#diff-a5cc3ff8c761716ba33b328ad1d042dfR1499

And also add an extension for test.

complexTruediv will pass subtype of float to complexDivFloat,
so loose the type check in complexDivFloat, use PyFloat_Check
instead check the type exactly.

For some struct member in Pyston itself, add `const` qualifier,
for exenstion, do not add `const` for compatibility reason.

Pyston's PyInt_AsLong implementation didn't check tp_as_number->nb_int,
use CPython implementation with some Pyston modifications to avoid
recursive call.

I think LLVM-tier compilation times got worse with refcounting,
which is why we've seen these tests time out more often lately.

this also workarounds the problem we were having on ubuntu 16.04 where we have to use std::isinf instead of isinf()

also add a option to pass MAP_32BIT to mmap

also fix a build error when ICs are disabled

I am not exactly sure why this ends up failing, but on my 15.10
machine I get the SSLv3 protocol but it ends up failing when the
test tries to connect.

CPython made this change, so copy it.

Temporarily disable the clang build on travis-CI

Somehow this PR is taking longer to build, I assume from somehow missing
the build cache.

Assuming that it's a caching issue, bump up the time to satisfy un-cached builds.
If build times continue to increase we will run into this problem again (can only
regenerate the cache with a successful build but a successful build needs the cache),
but this will let us defer it a bit longer :)  Travis-CI builds are max 120 minutes.

Fix std::move error on temporary object

since we were installing it from the LLVM APT repo, which they
took down since it was getting too expensive.  I guess we can
just run with the gcc build until that situation gets resolved.

exec, input: if globals has no __builtins__ add it as a dictwrapper

update list of failing cpython tests

Bump version numbers