allow check-cfg for rust 1.80

Author: tesuji

build.rs

@@ -7,6 +7,7 @@ use std::str;
 // make sure to add it to this list as well.
 const ALLOWED_CFGS: &'static [&'static str] = &[
     "emscripten_new_stat_abi",
+    "espidf_time64",
     "freebsd10",
     "freebsd11",
     "freebsd12",
@@ -35,7 +36,7 @@ fn main() {
     let (rustc_minor_ver, is_nightly) = rustc_minor_nightly();
     let rustc_dep_of_std = env::var("CARGO_FEATURE_RUSTC_DEP_OF_STD").is_ok();
     let libc_ci = env::var("LIBC_CI").is_ok();
-    let libc_check_cfg = env::var("LIBC_CHECK_CFG").is_ok();
+    let libc_check_cfg = rustc_minor_ver >= 80 || env::var("LIBC_CHECK_CFG").is_ok();
     let const_extern_fn_cargo_feature = env::var("CARGO_FEATURE_CONST_EXTERN_FN").is_ok();
 
     // The ABI of libc used by std is backward compatible with FreeBSD 12.

libc-test/test/makedev.rs

@@ -79,7 +79,7 @@ mod t {
 
     // These OSes allow 32 bits for both minor and major
     #[cfg(any(
-        target_os = "empscripten",
+        target_os = "emscripten",
         target_os = "freebsd",
         target_os = "fuchsia",
         target_os = "linux",