fixed serialize/unserialize for SplObjectStorage

added error handling for bad serialized strings according to zend tests.
We cannot move the actual tests from "bad" to "good" because ATM they
rely on the internal serialized string format of SplObjectStorage, which
is not yet reimplemented.

Closes #969

Differential Revision: D935251
Remove some dead profiling code

This profiling path was unused after D894723. Removing it.

Differential Revision: D934477
multiple simplexml fixes

- multiple fixes for simplexml required by magento

Closes #790
Closes #819
Closes #955

Differential Revision: D925428
move more helpers out of code-gen

Move more stateless platform dependent and agnostic helpers out of
code-gen.cpp

Differential Revision: D936727
use trigger_error in PHP for Redis user errors

- trigger_error is intended for reporting user errors, not
error_log

Closes #970

Differential Revision: D937921
Reduce bad error spam on too few arguments

function foo($bar, $baz) { }
  foo();

Currently raises two errors:

  foo() expects exactly 2 parameters, 0 given
  foo() expects exactly 2 parameters, 1 given

Only the first of these is either meaningful or correct.
Stop reporting once we've raised it.

Differential Revision: D939810
fallback to default separators in number_format

When number_format receives 'null' for one of its separator parameters,
we must pass it back to t_number_format so it can decide whether or not
it should fallback to its default separators.

Currently, when passing NULL to a parameter that is defined as String,
it is implicitly converted to an empty string, and subsequently
str.isNull() will return false.

Instead, we use a Variant with a default string value.

Closes #982

Differential Revision: D940482
ReflectionProperty(null,null) should throw

ReflectionProperty constructor should reject nulls

Closes #975

Differential Revision: D939337
Support "(new Vector {..})->method()" style syntax

This diff adds support for calling methods directly on collection literal
expressions (as long as the collection literal is wrapped in parentheses).

Differential Revision: D940562
Move util/zend (which defines zend.a) up one level.

And rename _ to - while we're at it.

Differential Revision: D925182