bpo-40423: Optimization: use close_range(2) if available (GH-22651)
close_range(2) should be preferred at all times if it's available, otherwise we'll use closefrom(2) if available with a fallback to fdwalk(3) or plain old loop over fd range in order of most efficient to least.
[note that this version does check for ENOSYS, but currently ignores all other errors]
Automerge-Triggered-By: @pablogsal
diff --git a/configure b/configure
index ad74754..89577d8 100755
--- a/configure
+++ b/configure
@@ -11672,8 +11672,8 @@
# checks for library functions
for ac_func in alarm accept4 setitimer getitimer bind_textdomain_codeset chown \
- clock confstr copy_file_range ctermid dup3 execv explicit_bzero explicit_memset \
- faccessat fchmod fchmodat fchown fchownat \
+ clock confstr close_range copy_file_range ctermid dup3 execv explicit_bzero \
+ explicit_memset faccessat fchmod fchmodat fchown fchownat \
fdwalk fexecve fdopendir fork fpathconf fstatat ftime ftruncate futimesat \
futimens futimes gai_strerror getentropy \
getgrgid_r getgrnam_r \