Auto merge of #3060 - shikhapanwar:sycfs_for_android, r=JohnTitor

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.

libc-test/build.rs

@@ -1511,6 +1511,7 @@ fn test_android(target: &str) {
         t => panic!("unsupported target: {}", t),
     };
     let x86 = target.contains("i686") || target.contains("x86_64");
+    let arm = target.contains("arm") || target.contains("aarch64");
 
     let mut cfg = ctest_cfg();
     cfg.define("_GNU_SOURCE", None);
@@ -1813,6 +1814,9 @@ 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" if arm => true,
+
             _ => false,
         }
     });

libc-test/semver/android.txt

@@ -3530,6 +3530,7 @@ swapoff
 swapon
 symlink
 symlinkat
+syncfs
 syscall
 sysconf
 sysinfo

src/unix/linux_like/android/mod.rs

@@ -3510,6 +3510,8 @@ extern "C" {
         longopts: *const option,
         longindex: *mut ::c_int,
     ) -> ::c_int;
+
+    pub fn syncfs(fd: ::c_int) -> ::c_int;
 }
 
 cfg_if! {