bpo-39406: Implement os.putenv() with setenv() if available (GH-18128)
If setenv() C function is available, os.putenv() is now implemented
with setenv() instead of putenv(), so Python doesn't have to handle
the environment variable memory.
diff --git a/configure.ac b/configure.ac
index bcef99c..36c165b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3600,7 +3600,7 @@
posix_fallocate posix_fadvise posix_spawn posix_spawnp pread preadv preadv2 \
pthread_condattr_setclock pthread_init pthread_kill putenv pwrite pwritev pwritev2 \
readlink readlinkat readv realpath renameat \
- sem_open sem_timedwait sem_getvalue sem_unlink sendfile setegid seteuid \
+ sem_open sem_timedwait sem_getvalue sem_unlink sendfile setegid setenv seteuid \
setgid sethostname \
setlocale setregid setreuid setresuid setresgid setsid setpgid setpgrp setpriority setuid setvbuf \
sched_get_priority_max sched_setaffinity sched_setscheduler sched_setparam \