Test custom branch of assetic with un-flakeyed test

It's either this or clownlist it.

PR up for same change in master.

Reviewed By: @JoelMarcey

Differential Revision: D1221634
Miscellaneous bugfixes

There was a bug in the check for state compatibility of
merges that was preventing us from actually generating many regions
with bytecode control flow.  Fixing that bug uncovered some other
issues that are also fixed here.

Reviewed By: @swtaarrs

Differential Revision: D1219074
Fix crash in ArrayObject

The call to ElemDObject here was incorrectly forwarding keyType. The
call to initScratchKey at the beginning of the function modifies key to point
to a real TypedValue, so any subsequent uses of key need to use KeyType::Any.

This would've been prevented if we were using a proper Key type instead of
abusing TypedValue*, which is something I tried to do a while ago. It
inexplicably caused a perf regression at the time so I abandoned it, but that
was with an old gcc so we should try again.

Closes #1948

Reviewed By: @bertmaher

Differential Revision: D1221410
Reset max object and resource ids for each request

They were previously only being cleared if a thread died.

Reviewed By: @markw65

Differential Revision: D1219626
Put back ::relaxNGValidate

The methods on the object are actually there, so we might as well have the procedural ones.

Reviewed By: @fredemmott

Differential Revision: D1221520
Rerecord some expectf files to be more specific

Prep work for sedding all error messages. Re-recorded with out2expectf

- test/slow/ext_imagick/php_imagick_tests/020_pixeliterator.php
- test/slow/serialization/private_properties.php

Reviewed By: @ptarjan

Differential Revision: D1221715
Change format of all error messages to be compatible with PHP5

.phpt tests in open source projects frequently rely on this. We need to match.

- Remove 'HipHop' from all
- Add newline before error messages

This is just sed:
```
find hphp -type f -name '*.expect*' | xargs sed -i 's/HipHop \(Warning\|Notice\|Error\|Fatal error\|Strict Warning\)/\n\1/g'
find hphp -type f ! -name '*.expect*' | xargs sed -i 's/HipHop \(Warning\|Notice\|Error\|Fatal error\|Strict Warning\)/\\n\1/g'
```

Reviewed By: @ptarjan

Differential Revision: D1209774
Update Native checker

Update C*Ref argument types to const versions
Handle static C++ functions
Trim the C++ value so that newlines get handled
Functions with more than 5 args need to be ActRec

Closes #2024

Reviewed By: @ptarjan

Differential Revision: D1221966

Pulled By: @sgolemon
Simplify ExecutionContext::enterVM()

Simplify ExecutionContext::enterVM():

- merge enterVMWork(non-null)+enterVMPrologue() into enterVMAtFunc()
- inline null in enterVMWork(null) into enterVMAtCurPC()
- stricten assertions about m_pc being legal in m_fp->func()
- fix double Stats::inc(Stats::VMEnter) when not using jit in enterVMPrologue()

Reviewed By: @markw65

Differential Revision: D1220404
Temporarily disable flaky tests

Reviewed By: @jdelong
Remove uses xsltprocessor uses of a few Variant apis that are about to go

Variant::instanceof and Variant::append are going away.

Reviewed By: @fredemmott

Differential Revision: D1214577
Send a few helper routines closer to where they are used

Reviewed By: @ptarjan

Differential Revision: D1210784
Rework register_variable to use Array instead of Variant

Removes a use of Variant's array-like functions, and should
make this code path somewhat faster.  (Now it won't repeatedly check
if $_ENV is an array over and over.)

Reviewed By: @ptarjan

Differential Revision: D1210838
Remove Variant::rval* and Variant::operator[]

Reviewed By: @alexmalyshev

Differential Revision: D1210940
Remove pop, prepend, and dequeue from Variant/VRefParamValue

Reviewed By: @ptarjan

Differential Revision: D1210941
Remove unused Variant::cast member function template

Reviewed By: @ptarjan

Differential Revision: D1210942
Remove some iterator functions from Variant

Reviewed By: @ptarjan

Differential Revision: D1210943
Move Variant::getAPCHandle out of Variant

Single caller can just do it themselves.

Reviewed By: @dariorussi

Differential Revision: D1210944
Add a helper function to force a Variant to contain an array

Reviewed By: @markw65

Differential Revision: D1219690
Remove Variant's lval member functions

Reviewed By: @markw65

Differential Revision: D1210945