ANDROID: Add syncfs API in liblibc

This is required to sync everything in a single filesystem. Other
solutions like sync() flushes all filesystems which is unnecessary, it
is also impractical to call fsync on all files of the filesystem.

This patch also excludes syncfs for arm from CI.

Author: Shikha Panwar

libc-test/build.rs

@@ -1806,6 +1806,9 @@ fn test_android(target: &str) {
             // Added in API level 28, but some tests use level 24.
             "getrandom" => true,
 
+            // Added in API level 28, but some tests use level 24.
+            "syncfs" => true,
+
             _ => false,
         }
     });

libc-test/semver/android.txt

@@ -3517,6 +3517,7 @@ swapoff
 swapon
 symlink
 symlinkat
+syncfs
 syscall
 sysconf
 sysinfo

src/unix/linux_like/android/mod.rs

@@ -3506,6 +3506,8 @@ extern "C" {
         longopts: *const option,
         longindex: *mut ::c_int,
     ) -> ::c_int;
+
+    pub fn syncfs(fd: ::c_int) -> ::c_int;
 }
 
 cfg_if! {