remove flag ZEND_DEBUG check for ZEND_ASSERT

[jorgsowa]

Flag ZEND_DEBUG is checked anyway in macro ZEND_ASSERT, so this code is redundant.

[dstogov]

Without ZEND_DEBUG, ZEND_ASSERT is expanded to ZEND_ASSUME that is not always free. Especially in this place it leaded to a worse final code.

[jorgsowa]

Sorry. I thought it should be the same as for functions below zval_set_refcount_p or zval_addref_p.

[iluuu1994]

@dstogov On GCC, with if (__builtin_expect(!(c), 0)) __builtin_unreachable();? That is surprising to me...

If that's the case, we may try to move to __attribute__((assume(...)));, which is apparently supported on GCC in C (https://gcc.gnu.org/onlinedocs/gcc/Statement-Attributes.html#Statement-Attributes-1).

[dstogov]

@dstogov On GCC, with if (__builtin_expect(!(c), 0)) __builtin_unreachable();? That is surprising to me...

In most cases this should be eliminated by the compiler and also help to optimise the program, but in some cases (when condition may make a side effect) this may lead to extra code.

[iluuu1994]

@dstogov According to the documentation, __attribute__((assume(...))) is guaranteed not to have side-effects, so maybe we should try that.

[jorgsowa]

If #13171 is merged, does it mean that this PR can be merged also?

[iluuu1994]

@jorgsowa No, #13171 is only applicable to GCC 13.