stty/flags: List all missing flags that GNU version supports

List the remaining flags that GNU stty support, they cannot be be listed
yet since we have no nix support for them, but it's better to keep the
lists in sync so that it's easier to enable what will be supported in
future

Author: 3v1n0

src/uu/stty/src/flags.rs

@@ -65,10 +65,14 @@ pub const CONTROL_FLAGS: &[Flag<C>] = &[
     Flag::new_grouped("cs7", C::CS7, C::CSIZE),
     Flag::new_grouped("cs8", C::CS8, C::CSIZE).sane(),
     Flag::new("hupcl", C::HUPCL),
+    // Not supported by nix.
+    // Flag::new("hup", C::HUP).hidden(),
     Flag::new("cstopb", C::CSTOPB),
     Flag::new("cread", C::CREAD).sane(),
     Flag::new("clocal", C::CLOCAL),
     Flag::new("crtscts", C::CRTSCTS),
+    // Not supported by nix.
+    // Flag::new("cdtrdsr", C::CDTRDSR),
 ];
 
 pub const INPUT_FLAGS: &[Flag<I>] = &[
@@ -120,6 +124,15 @@ pub const OUTPUT_FLAGS: &[Flag<O>] = &[
         target_os = "linux",
         target_os = "macos"
     ))]
+    // Not supported by nix.
+    // Flag::new("ofill", O::OFILL),
+    // #[cfg(any(
+    //     target_os = "android",
+    //     target_os = "haiku",
+    //     target_os = "ios",
+    //     target_os = "linux",
+    //     target_os = "macos"
+    // ))]
     Flag::new_grouped("nl0", O::NL0, O::NLDLY).sane(),
     #[cfg(any(
         target_os = "android",
@@ -377,6 +390,14 @@ pub const CONTROL_CHARS: &[(&str, S)] = &[
     ("lnext", S::VLNEXT),
     // Discards the current line.
     ("discard", S::VDISCARD),
+    // deprecated compat option.
+    // ("flush", S::VFLUSHO), // Not supported by nix
+    // Status character
+    // ("status", S::VSTATUS), // Not supported by nix
+    // Minimum number of characters for noncanonical read.
+    // ("min", S::VMIN),
+    // Timeout in deciseconds for noncanonical read.
+    // ("time", S::VTIME),
 ];
 
 /// This constant lists all possible combination settings, using a bool to represent if the setting is negatable