Configure blows up because of implicit declaration of exit()

[Artoria2e5]

Current git HEAD gives:

configure:9081: checking compiler and flags for sanity
configure:9095: gcc -o conftest -g -O2 -fPIC -Wall -Wpointer-arith -Wuninitialized -fstack-protector-all -fno-common  -I/usr/local/opt/icu4c/include -I/usr/local/opt/ruby/include -I/usr/local/opt/sqlite/include -I/usr/local/opt/gettext/include -I/usr/local/opt/qt/include  -L/usr/local/opt/icu4c/lib -L/usr/local/opt/ruby/lib -L/usr/local/opt/sqlite/lib -L/usr/local/opt/gettext/lib -L/usr/local/opt/qt/lib -fstack-protector-all conftest.c  >&5
conftest.c:134:12: error: call to undeclared library function 'exit' with type 'void (int) __attribute__((noreturn))'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
int main(){exit(0);}
           ^
conftest.c:134:12: note: include the header <stdlib.h> or explicitly provide a declaration for 'exit'
1 error generated.
configure:9095: $? = 1
configure: program exited with status 1
configure: failed program was:
| /* confdefs.h, irrelevant */
| /* end confdefs.h.  */
| 
| #include <stdio.h>
| int main(){exit(0);}
| 
configure:9100: result: no
configure:9102: error: *** compiler cannot create working executables, check config.log ***

gcc --version gives:

Apple clang version 15.0.0 (clang-1500.0.40.1)
Target: x86_64-apple-darwin22.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

Running autoreconf does not help, because this test is written directly in configure.ac. Changing the CFLAGS to add -Wno-error=all at the CFLAGS="$CFLAGS -fPIC -Wall -Wpointer-arith -Wuninitialized" bit helps, but the right way to do it is probably fixing the invocation. Because well, the compiler does not seem to be in the wrong here.