Introduce new time retrieval Zend-API

[marc-mabe]

This is split out from #19202 to first introduce the new time retrieval API. Later PRs will follow to refactor time retrieval usages.

Key Changes

• Introduced zend_time.h
  A new internal header that abstracts system time functions, replacing direct usage of <time.h> and related platform-specific APIs.

• Added zend_time_real_spec
  A unified wrapper around clock_gettime(), timespec_get(), gettimeofday(), and time() using the real/wall clock.
  Returns a timespec structure with up-to nanosecond precision.

• Added zend_time_real_sec
  A lightweight wrapper around time(NULL) for simple, low-resolution time retrieval in seconds.

• Added zend_time_mono_fallback_nsec
  A wrapper for zend_hrtime or falls back to zend_time_real_spec.
  Useful for time measurements (e.g. timeout handling) where monotonic time is preferred, but wall time is an acceptable fallback.

• Added helper functions
  Added utilities to simplify usage of timeval and timespec structures.

The time retrieval functions are not inlined to make it possible to be mocked in unit tests.

[TimWolla]

The time retrieval functions are not inlined to make it possible to be mocked in unit tests.

Is it really necessary to mock them rather than mocking their implementation default? Not allowing them to be inlined is likely going to make them expensive for basically only being a wrapper.

[marc-mabe]

Is it really necessary to mock them rather than mocking their implementation default? Not allowing them to be inlined is likely going to make them expensive for basically only being a wrapper.

I have inlined zend_time_real_sec as this wraps time() only. For mocking zend_time_real_spec and zend_time_mono_fallback_nsec it would require to know which underlying function to mock (as in

php-src/tests/unit/main/test_network.c

Line 40 in 53e31d5

int __wrap_gettimeofday(struct timeval *time_Info, struct timezone *timezone_Info)

) effectively repeating the pre-compiler logic in the unit test.

[kocsismate]

My #21715 PR desperately needs this API, so I would appreciate if it could be merged soon. Thanks, Marc, for working on this topic!

[marc-mabe]

@TimWolla @derickr Now all functions do return instead of pointer-out.
Hope it's good to go now.