Update folly
Modify PHP's ext/standard/math/tests/(pow|abs).phpt to be HHVM friendly

HHVM's arithmetic operators do not promote to double.
Use double-casted LONG_MIN/MAX to track this behavior.
Optimize InstanceOfD when rhs is unique interface

We would normally have to load the class and do
a whole bunch of other noise. Now we don't.
Move SessionModule class to ext_session's header

So that other extensions can register their own
Session Modules.
Mark CheckType non-CSEable

It's a control-flow instruction, and we don't support eliminating
control-flow yet.

This got exposed by the region/trace JIT.
relax guard change to allow for specialized guards

Unified code for relax and specialize guards and removed type propagation on relaxation
get HHVM to compile on OSX

This is a squash of https://github.com/danslo/hiphop-php/compare/osx-review
Fix native Exception::setPreviousChain() fatal

Fixes a fatal in native Exception, which is missing parentheses on this method call.
Allow AssertType of Cls

We need this with the region JIT.
Fix tools/reduce

The runtime option used by this script was renamed. Also, stop
retranslating as soon as JitGlobalTranslationLimit is reached.
ContSuspendK should break tracelets

It's a control-flow instruction.
Fix duplicate HTTP headers

When the same header is passed in, Apache/PHP will comma delimit
all header values for the returned values in apache_request_headers
and $_SERVER['HTTP_*'].