CONTEXT
I am running an 2015 intel macbook air
Apple has their own compiler called appleclang that is their own version of clang
SUMMARY
I was building the KCodecs framework where I got error about the "register" storage class specifier not being allowed any more
STEPS TO REPRODUCE
1. Have an apple computer on macos sequoia
2. clone Kcodecs gitlab
3. try to build & compile it

OBSERVED RESULT
[ 58%] Building CXX object src/CMakeFiles/KF6Codecs.dir/kcharsets.cpp.o
In file included from /Users/daniel/Programs/kframe/kcodecs/src/kcharsets.cpp:14:
/Users/daniel/Programs/kframe/kcodecs/src/kentities.gperf:40:31: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
   40 | KCodecsEntities::hash_Entity (register const char *str, register unsigned int len)
      |                               ^~~~~~~~
/Users/daniel/Programs/kframe/kcodecs/src/kentities.gperf:40:57: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
   40 | KCodecsEntities::hash_Entity (register const char *str, register unsigned int len)
      |                                                         ^~~~~~~~
/Users/daniel/Programs/kframe/kcodecs/src/kentities.gperf:71:3: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
   71 |   register unsigned int hval = len;
      |   ^~~~~~~~
/Users/daniel/Programs/kframe/kcodecs/src/kentities.gperf:104:34: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
  104 | KCodecsEntities::kde_findEntity (register const char *str, register unsigned int len)
      |                                  ^~~~~~~~
/Users/daniel/Programs/kframe/kcodecs/src/kentities.gperf:104:60: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
  104 | KCodecsEntities::kde_findEntity (register const char *str, register unsigned int len)
      |                                                            ^~~~~~~~
/Users/daniel/Programs/kframe/kcodecs/src/kentities.gperf:397:11: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
  397 |           register int index = lookup[key];
      |           ^~~~~~~~
/Users/daniel/Programs/kframe/kcodecs/src/kentities.gperf:401:15: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
  401 |               register const char *s = wordlist_Entity[index].name;
      |               ^~~~~~~~
/Users/daniel/Programs/kframe/kcodecs/src/kentities.gperf:408:10: warning: zero as null pointer constant [-Wzero-as-null-pointer-constant]
  408 |   return 0;
      |          ^
      |          nullptr
1 warning and 7 errors generated.
make[2]: *** [src/CMakeFiles/KF6Codecs.dir/kcharsets.cpp.o] Error 1
make[1]: *** [src/CMakeFiles/KF6Codecs.dir/all] Error 2
make: *** [all] Error 2
EXPECTED RESULT
I expected it to build & compile without errors
SOFTWARE/OS VERSIONS
macOS: Sequoia
ADDITIONAL INFORMATION
N/A