Fix undefined flags in base64

[jorgsowa]

Part of #5526 for base64 ext.

I'm not sure about failing the test. Looks like it's not related.

Checks for flags:

• ZEND_INTRIN_AVX2_NATIVE
• ZEND_INTRIN_AVX2_FUNC_PROTO
• ZEND_INTRIN_AVX2_FUNC_PTR
• ZEND_INTRIN_AVX2_RESOLVER
• ZEND_INTRIN_SSSE3_NATIVE
• ZEND_INTRIN_SSSE3_RESOLVER
• ZEND_INTRIN_SSSE3_FUNC_PROTO
• ZEND_INTRIN_AVX512_FUNC_PROTO
• ZEND_INTRIN_AVX512_FUNC_PTR
• ZEND_INTRIN_AVX512_VBMI_FUNC_PROTO
• ZEND_INTRIN_AVX512_VBMI_FUNC_PTR
• BASE64_INTRIN_AVX512_VBMI_FUNC_PTR
• BASE64_INTRIN_AVX512_VBMI_FUNC_PROTO
• BASE64_INTRIN_AVX512_FUNC_PTR
• BASE64_INTRIN_AVX512_FUNC_PROTO
• BASE64_INTRIN_AVX512_VBMI_FUNC_PTR
• HAVE_FUNC_ATTRIBUTE_TARGET

[petk]

This would still be good to fix at some point I think. There are a lot of these, yes.

[jorgsowa]

There are still many such cases but this required reviews. I assume there are more important things to tackle than this. I don't want to spam with such PRs so I just closed it. It's better probably to merge Girgias's PR at once.

[petk]

I think it would be better to do it in multiple PRs like this one. There are too many of these for a single PR because some 0/1 value can get quickly missed - I've seen this in the past on few places and it can introduce a bigger bug than before. And BTW, I'm hitting such issues daily with my build. So from my PoV all such fixes are a high priority.

I think all is good here to merge. It only needs to be rebased against the master branch.

[jorgsowa]

I couldn't reopen PR, so I recreated it. If it's a priority issue then I can spend time fixing it.

#14316