Reenable grp header (for git)

src/header/grp/cbindgen.toml

@@ -0,0 +1,7 @@
+sys_includes = []
+include_guard = "_GRP_H"
+language = "C"
+style = "Tag"
+
+[enum]
+prefix_with_name = true

src/header/grp/mod.rs

@@ -0,0 +1,65 @@
+//! grp implementation for Redox, following http://pubs.opengroup.org/onlinepubs/7908799/xsh/grp.h.html
+
+use platform::types::*;
+
+#[repr(C)]
+pub struct group {
+    pub gr_name: *mut c_char,
+    pub gr_passwd: *mut c_char,
+    pub gr_gid: gid_t,
+    pub gr_mem: *mut *mut c_char,
+}
+
+// #[no_mangle]
+pub extern "C" fn getgrgid(gid: gid_t) -> *mut group {
+    unimplemented!();
+}
+
+// #[no_mangle]
+pub extern "C" fn getgrnam(name: *const c_char) -> *mut group {
+    unimplemented!();
+}
+
+// #[no_mangle]
+pub extern "C" fn getgrgid_r(
+    gid: gid_t,
+    grp: *mut group,
+    buffer: *mut c_char,
+    bufsize: usize,
+    result: *mut *mut group,
+) -> c_int {
+    unimplemented!();
+}
+
+// #[no_mangle]
+pub extern "C" fn getgrnam_r(
+    name: *const c_char,
+    grp: *mut group,
+    buffer: *mut c_char,
+    bufsize: usize,
+    result: *mut *mut group,
+) -> c_int {
+    unimplemented!();
+}
+
+// #[no_mangle]
+pub extern "C" fn getgrent() -> *mut group {
+    unimplemented!();
+}
+
+// #[no_mangle]
+pub extern "C" fn endgrent() {
+    unimplemented!();
+}
+
+// #[no_mangle]
+pub extern "C" fn setgrent() {
+    unimplemented!();
+}
+
+/*
+#[no_mangle]
+pub extern "C" fn func(args) -> c_int {
+    unimplemented!();
+}
+*/