As described in autoconf-archive upstream [1], from where
`build/ax_gcc_func_attribute.m4` is forked, the old unknown func attr
detection method would throw a false negative anytime an unrelated
warning was raised.
This results in `ax_cv_have_func_attribute_target` being set to `no`
whenever certain compiler Warning flags are switched on. Namely, having
`-Wall` on, which is a default CFLAG for some linux distributions, will
result in
```
warning: ‘bar’ declared ‘static’ but never defined [-Wunused-function]
```
when evaluating support for the `target` function attribute.
With that configuration value set to `no`, the compiled php binaries
will not support x86_64 v3 instructions such as avx2 and sse2, which
should speed up specific tasks ran by PHP.
This issue was originally reported in Ubuntu [2].
[1] http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=commitdiff;h=df0894ad1a8195df67a52108b931e07d708cec9a
[2] https://bugs.launchpad.net/ubuntu/+source/php8.1/+bug/1882279
Closes GH-8483.
The only backing types for Enums are int and string. The proper return type for ReflectionEnum::getBackingType() is thus null|ReflectionNamedType.
See also https://github.com/php/doc-en/pull/1608
Closes GH-8687
This is done by adding a new zend_atomic_bool type. The type
definition is only available for compiler alignment and size info; it
should be treated as opaque and only the zend_atomic_bool_* family of
functions should be used.
Note that directly using atomic_bool is complicated. All C++ compilers
stdlibs that I checked typedef atomic_bool to std::atomic<bool>, which
can't be used in an extern "C" section, and there's at least one usage
of this in core, and probably more outside of it.
So, instead use platform specific functions, preferring compiler
intrinsics.
