Migrate SKIPIF -> EXTENSIONS (#7138)

This is an automated migration of most SKIPIF extension_loaded checks.

Rename zend-test to zend_test

The extension name should match the name of the ext/ directory,
otherwise it will not get picked up by run-tests. It would be possible
to remap this in

Rename zend-test to zend_test

The extension name should match the name of the ext/ directory,
otherwise it will not get picked up by run-tests. It would be possible
to remap this in run-tests, but I think it's better to rename the
extension to follow the standard format. Other extensions also
use underscore instead of hyphen (e.g. pdo_mysql and not pdo-mysql).
Of course, the ./configure option remains hyphenated.

Closes GH-6613.

show more ...

Add support for deprecating constants

Internal constants can be marked as CONST_DEPRECATED, in which
case accessing them will throw a deprecation warning.

For now this is only s

Add support for deprecating constants

Internal constants can be marked as CONST_DEPRECATED, in which
case accessing them will throw a deprecation warning.

For now this is only supported on global constants, not class
constants. Complain to me if you need to deprecate a class
constant...

Closes GH-5072.

show more ...