posixmodule "undeclared function" error when compiling with sanitizer options on Termux (Android)

Python fails to compile when compiling with the sanitizer option.

Python/fileutils.c:458:1: warning:                  unused function 'decode_current_locale'       [-Wunused-function]                       458 | decode_current_locale(const char* arg...                                                  | ^~~~~~~~~~~~~~~~~~~~~                 
Python/fileutils.c:677:1: warning:                  unused function 'encode_current_locale'       [-Wunused-function]                       677 | encode_current_locale(const wchar_t *t...                                                 | ^~~~~~~~~~~~~~~~~~~~~                 2 warnings generated.                         
./Modules/posixmodule.c:10400:15: error:            call to undeclared function 'wait3'; ISO      C99 and later do not support implicit         function declarations                         [-Wimplicit-function-declaration]        10400 |         pid = wait3(&status, options, &ru);                                               |               ^                      1 error generated.                            make: *** 
[Makefile:3808: Modules/posixmodule.o] Error 1                                    make: *** Waiting for unfinished jobs...

clang option use.

aarch64-linux-android-clang -fsanitize=address -fsanitize=undefined
aarch64-linux-android-clang++ -fsanitize=address -fsanitize=undefined -fno-sanitize=vptr

aarch64-linux-android-clang --version                                  
 clang version 21.1.3                         
 Target: aarch64-unknown-linux-android24       
Thread model: posix                           
InstalledDir: /data/data/com.termux/files/usr/bin

.git revision is at bedaea05987738c4c6b958d19cec9621bec09f07

Compiling with no sanitizer option works.

Start in Modules/posixmodule.c around the wait3 call reported near line 10400, then reproduce the build with the provided Termux clang sanitizer commands and the no-sanitizer configuration for comparison. Done means CPython compiles with the sanitizer options without the undeclared-function error.