Revert "make simplexml xpath return original objects"

This reverts commit d44b74fec1c4c01114185cc84009bbb1562ca716.

Reviewed By: @jdelong

Differential Revision: D960763
Fix bug that omitted VerifyParamTypes on Xhp hints

This was only supposed to omit ?Xhp checks, but I messed it
up ....

Reviewed By: @markw65

Differential Revision: D957536
Fix compare() bug in TypeAnnotation::dataType()

Fix comparison logic in TypeAnnotation::dataType(), which was causing
the result of f_hash_algos() to be type-punned from KindOfArray to
KindOfObject.

Reviewed By: @markw65

Differential Revision: D961159
fix inlining warnings

Noticed these warnings when building on OSX.

Reviewed By: @jdelong

Differential Revision: D958997
Improve RecursiveIteratorIterator Zend compat

- Added methods and callbacks: beginChildren, beginIteration, callGetChildren, callHasChildren, endChildren, endIteration, getDepth, getMaxDepth, getSubIterator, nextElement, setMaxDepth.

Closes #1006

Reviewed By: @ptarjan

Differential Revision: D953349

Pulled By: @scannell