Auto merge of #3499 - Takashiidobe:ent-calls, r=JohnTitor

Add group calls to android

Following #3014, this PR just implements the group side of the calls, since that doesn't require CI to be updated.

Author: bors

libc-test/semver/android.txt

@@ -3110,6 +3110,7 @@ dlsym
 dup
 dup2
 duplocale
+endgrent
 endservent
 epoll_create
 epoll_create1
@@ -3212,6 +3213,7 @@ getegid
 getenv
 geteuid
 getgid
+getgrent
 getgrgid
 getgrgid_r
 getgrnam
@@ -3609,6 +3611,7 @@ seteuid
 setfsgid
 setfsuid
 setgid
+setgrent
 setgroups
 sethostname
 setlocale

src/unix/linux_like/android/mod.rs

@@ -3570,6 +3570,9 @@ safe_f! {
 }
 
 extern "C" {
+    pub fn setgrent();
+    pub fn endgrent();
+    pub fn getgrent() -> *mut ::group;
     pub fn getrlimit64(resource: ::c_int, rlim: *mut rlimit64) -> ::c_int;
     pub fn setrlimit64(resource: ::c_int, rlim: *const rlimit64) -> ::c_int;
     pub fn getrlimit(resource: ::c_int, rlim: *mut ::rlimit) -> ::c_int;