Zend: Add unsigned suffix for bitmask flags

[Girgias]

Bit shifts are only well-defined for unsigned integers:

The integer promotions are performed on each of the operands. The type of the result is that of the
promoted left operand. If the value of the right operand is negative or is greater than or equal to the
width of the promoted left operand, the behavior is undefined

Section 6.5.7 Bitwise shift operators of the latest C23 draft (and this is also valid in C99): https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf

Moreover, a lot of the results of these flags are stored in uint32_t fields.

This is part of being able to enable the -Wconversion warning.

[dstogov]

What does this fix?
The following C code doesn't cause conversion warnings (nor GCC neither CLANG with -Wsign-conversion)

void test() {
	unsigned x = 1 << 5;
}

[Girgias]

The issue is if you enable the -Wconversion flag, you will get warnings such as:

/home/girgias/Dev/php-src/Zend/zend_hash.h:1615:19: warning: implicit conversion changes signedness: 'int' to 'uint32_t' (aka 'unsigned int') [-Wsign-convers>
 1615 |                 HT_FLAGS(ht) &= ~HASH_FLAG_STATIC_KEYS;
      |                              ~~ ^~~~~~~~~~~~~~~~~~~~~~

because the signed bitmask flag is being assigned to an unsigned struct field. And because virtually all fields in Zend that are bitmask flags are of type uint32_t each individual flag also be unsigned IMHO.

I'll fix the description of the PR as it is indeed the wrong compiler flag I mentioned.

[dstogov]

The issue is if you enable the -Wconversion flag, you will get warnings such as:

/home/girgias/Dev/php-src/Zend/zend_hash.h:1615:19: warning: implicit conversion changes signedness: 'int' to 'uint32_t' (aka 'unsigned int') [-Wsign-convers>
 1615 |                 HT_FLAGS(ht) &= ~HASH_FLAG_STATIC_KEYS;
      |                              ~~ ^~~~~~~~~~~~~~~~~~~~~~

because the signed bitmask flag is being assigned to an unsigned struct field. And because virtually all fields in Zend that are bitmask flags are of type uint32_t each individual flag also be unsigned IMHO.

You are right. May be changing the left operand of the shift is enough?

void test(unsigned *p) {
	*p &= ~(1U << 5);
}

It looks like Rust changes the mind of C compilers developers and we have to bloat the source code with more and more qualifications... :)