FAST_ZPP for hot functions
Fixed bug #68644 (strlen incorrect : mbstring + func_overload=2 +UTF-8 + Opcache)
Merge branch 'PHP-5.6'

Conflicts:
	ext/opcache/Optimizer/pass1_5.c
Update NEWs
Added new API function 'zend_string* zend_string_tolower(zend_string*)'.
It simplifies code and avoids unnecessary allocation and copying if string is already in lower case.
For disabled function, to disable arguments checks, we have to reset num_args and some related flags (in addition to arg_info)
No need to do this check for master, ZEND_COMPILE_NO_BUILTIN_STRLEN already cover it
Merge branch 'master' of https://git.php.net/repository/php-src
C89 compat
remove unused variable
Use zend_string_tolower in zif_strtolower
Merge branch 'master' of https://git.php.net/repository/php-src
Revert "Use zend_string_tolower in zif_strtolower"

This reverts commit 06abeab50c00fce1e8f06a8a137d4760ac13acae.
Add php_string_tolower/toupper which is locale depened
Fixed tests fails
Revert "Fix failing tests"

This fix break test due to precision setting

This reverts commit 4e2c01617f207c039881f635d3beb77eff0d9669.

Conflicts:
	ext/mysqli/tests/mysqli_change_user.phpt
	ext/mysqli/tests/table.inc
Fixed test
Re-apply part fix of 4e2c016