Implement +=, -=, *=, /= and %= outside of Variant
Combine IssetM and EmptyM implementations
Delete some dead code in NameValueTableWrapper and SharedMap
Separate resources from objects, part 1

In HHVM (and HPHPc before it) we've been piggybacking resources on the
KindOfObject machinery. At the language level, resource is considered to
be a different type than object, and there are a number of differences
in behavior between objects and resources (ex. resources don't allow for
dynamic properties, resources don't work with the clone operator, the
"(object)" cast behaves differently for resources vs. objects, etc).

Piggybacking resources on the KindOfObject machinery has some downsides.
Code that deals with KindOfObject values often needs to check if the value
is a resource and go down a different code path. This makes things harder
to maintain and harder to keep parity with Zend. Also, these extra branches
hurt performance a little, and they make it harder for the JIT to do a good
job in some cases when its generating machine code that operates on objects.

This diff prepares the code base for a new KindOfResource type by adding a
new "Resource" smart pointer type (currently a typedef for the Object smart
pointer type) and it updates the C++ code and the idl files appropriately.
This diff is essentially a cosmetic change and should not impact run time
behavior. In the next diff (part 2) we'll actually add a new KindOfResource
type, detach ResourceData from the ObjectData inheritence hierarchy, and
provide a real implementation for the Resource smart pointer type (instead
of just aliasing the Object smart pointer type).
Remove operator==(Op, Opcode) and friends

I added them to ease the transition but since Opcode is just
uint8_t, they remove a lot of the safety of making Op an enum class.
Add simple functions to determine if a debugger is attached

Added two simple functions to determine if a debugger is attached, and to provide info about where the debugger is connected from. Also fixed a minor bug in ext_socket where the name for an unbound AF_UNIX socket would come back from getsocketname()/getpeername() as garbage.
Allow JIT-time known boxed types for source operand in cgCheckType

In the region JIT, we may end up with a CheckType on a source with a
known type that is boxed but different from the boxed type parameter
of CheckType.  We still want to keep such CheckType instruction to
communicate the type of its dest to the following code. However, that
instruction doesn't need to generate any code since the inner types
are checked at the uses (via LdRef).
Clean up VectorEffects::init

This is my attempt to clean up and simplify the logic in here
a bit. It also fixes a bug that we were hitting in the region
compiler: setting an element of a StaticStr may promote it to a
CountedStr.
OSX changes, next round

- fix merge issues
- remove platform-specific neo defines that were getting pulled in everywhere
- fix asm alignment directive on OSX
Move hopt_preparable.php to test/vm-perf

The goal of this benchmark was to measure performance, so increase the
number of iterations and move it out of test/quick.
Test's cpp files are moved to hphp/test/ext

Also create missing test_ext.inc
Don't double / file paths, it confuses poor CMake
Explicitly link libjemalloc into folly
Pass OS determination from CMake into gen-ext-hhvm.sh