Implemented SoapHeader properties

Summary: SoapHeader has public facing properties that can be manipulated. Those properties are undocumented.

Fixes #2822

Reviewed By: @fredemmott

Differential Revision: D1360488
Punt if framep is constant

Summary: Band-aid to prevent crashing; we still need to find out why
we're generating bogus IR.

Reviewed By: @markw65

Differential Revision: D1366150
Implement __toString() for reflection classes

Summary: ReflectionFunction
ReflectionMethod
ReflectionClass
ReflectionObject
ReflectionProperty
ReflectionParameter

Also...
* Found/fixed a crash in ReflectionClass::getOrderedConstants()
* Added missing function ReflectionClass::isIterable()

Closes #1571

Reviewed By: @fredemmott

Differential Revision: D1363317
Embed hhi files into hh_server binary

Summary: This will remove an annoying install step when getting started
with Hack.

Reviewed By: @elgenie

Differential Revision: D1353049
Read hhconfig to determine if we should use embedded hhi's

Summary: This is separate from D1353049 so that it can be separately
reverted. We need a transition plan for FB www, and this is simple. This
isn't such a huge deal for open-source users -- they can just delete
their hhi directories as part of their hh_server upgrade. For more
involved upgrades, we plan to go this path, except actually go an entire
OSS release with the config option present, and all sorts of automatic
upgrade stuff, but we don't have the machinery for that quite yet.

Reviewed By: @elgenie

Differential Revision: D1364920
Make hhi file valid

Summary: This should have been decl in the first place.

Reviewed By: @elgenie

Differential Revision: D1364934
fix a memory leak in simplexml

Summary: Oops, this one's on me. Since t_getiterator passes control over from the
sxe object to the iterator, we need to actually release sxe when our
iterator's destructor is called.

Fixes #2854.
Closes #2859

Reviewed By: @sgolemon

Differential Revision: D1366174

Pulled By: @JoelMarcey
Infer that IncDecL of an Int goes to Int in no-float-overflow mode

Reviewed By: @jdelong

Differential Revision: D1364180
Silence notice when fetching unset property via reflection

Summary: PHP5 doesn't throw an unset notice when we attempt
to fetch an unset value from a reflected object, so we shouldn't.

Closes #2013

Reviewed By: @JoelMarcey

Differential Revision: D1364543
Fix some arm bugs exposed by the tracelet region selector

Summary: I'm not sure why these weren't happening with analyze, but they're
real issues:
- When I did my vmfp/sp/pc refactor I missed a few accessors that need to be
  the unsafe versions.
- ARM::BackEnd::emitFwdJmp was unimplemented, and it's needed by the main
  codegen loop to link blocks together sometimes.

Reviewed By: @oyamauchi

Differential Revision: D1365090
Increase write lease's kStandardHintExpireInterval to 1500

Summary: I noticed some bad interleaving of translations in the TC that
suggested the write lease was expiring too soon.  So I experimented
with different values and tuned it.

Reviewed By: @swtaarrs

Differential Revision: D1365796
Add JIT support for Unbox bytecode instruction

Summary: I noticed we were always InterpOne'ing this instruction, and HHBBC
seems to have caused it to be generated more often (for cases it can
prove the result of a function is always boxed), resulting in bytecode
sequences like: FCallD ; BoxRNop ; Unbox

Reviewed By: @swtaarrs

Differential Revision: D1365851
remove cruft from RuntimeOption

Summary: The users of these were all removed over the years and these weren't deleted.

Reviewed By: @jdelong

Differential Revision: D1366696
Do not keep ptr to running async function, use runtime lookup instead

Summary: Do not update AsioContext::m_current everytime the currently executed
async function switches. Use runtime lookup instead.

Makes it easier to:

- switch running async functions from JIT
- unwind thru multiple async functions inside unwinder
- merge async stack trace into PHP stack trace

Makes it slower to retrieve async stack trace, but that cost will
disappear once we fully switch to unified stack trace. Hopefully the
extra cost is either not significant, or compensated by removed store
on the hot path.

Reviewed By: @jdelong

Differential Revision: D1365742
Disable some flaky tests

Summary: These have all failed one or more times on recent contbuild runs.

Reviewed By: @bertmaher

Differential Revision: D1368035
Fix stupid bug in hhconfig reading

Summary: Used the wrong function because I wasn't paying attention.

shark-derp

Reviewed By: @elgenie

Differential Revision: D1368049
Add YieldMethodDefaults builtin hhi file to fbcode

Reviewed By: @elgenie

Differential Revision: D1367262
Fix refcounting opts for bc control flow

Summary: With bytecode control flow, refcounts won't necessarily match
at a merge point, but they should obey the conditions described in the
comment on Value::merge.

Reviewed By: @edwinsmith

Differential Revision: D1363640
Corrected strtok for when tokenizer fails at the end of the string

Summary: `strtok` did not consider tokenizer failures resuling from eof after trying to tokenize.

Fixes #2860

Reviewed By: @ptarjan

Differential Revision: D1367181
remove mtime and prefetch

Summary: A long long time ago, the hack server was using message passing to implement the shared heap.
Back then, it was faster to batch the messages. Because of that, we were keeping the set of
classes and functions used by a node in the previous run to prefetch them the next time.
All of this is completely useless today, since we use shared memory, batching is not helping
what so ever!

Reviewed By: @elgenie

Differential Revision: D1365410