Test some additional cases for constexpr evaluation
Test error conditions for ct class const refs

And fix a bug found while doing so...
Test a few more error conditions in the compiler
Simply make_printable_zval

it's possible to remove make_printable_zval at all
but it will be a API break
Fixed typo
It is not likely a string
Make internal function names to be interned strings
Allocate copies of internal functions inherited in user classes at CG(arena), instead of permanent heap (malloc).
PR 837: Fixed typo in php.ini-development and php.ini-production

Fixed typo in comment for 'mbstring.detect_order'
Merge branch 'PHP-5.6'

* PHP-5.6:
  Fixed typo
Use zval_ptr_dtor_nogc() to free IS_TMP_VAR operands.
Removed ZEND_SWITCH_FREE opcode (ZEND_FREE used instead).
Drop dead code
Add zend_add_literal_string

And simplify additional of special literals based on it.
Test use of string names with \ prefix

And drop piece of dead code
Fix detection of write to built-in function for references
Fix ct binding for cuf/cufa functions

It was checking against the wrong AST kind, so the binding was
never actually done.
Drop unused result argument
Removed useless helper
Merge branch 'master' of git.php.net:php-src

* 'master' of git.php.net:php-src:
  Drop unused result argument
  Fix ct binding for cuf/cufa functions
  Fix detection of write to built-in function for references
  Test use of string names with \ prefix
  Add zend_add_literal_string
  Drop dead code
Make QM_ASSIGN, JMP_SET and CAST return IS_TMP_VAR.