Add fsyncNoInt, fdatasyncNoInt

Test Plan: compiled file_util_test

Reviewed By: soren@fb.com

FB internal diff: D809250

folly/FileUtil.cpp

@@ -41,6 +41,14 @@ int closeNoInt(int fd) {
   return r;
 }
 
+int fsyncNoInt(int fd) {
+  return wrapNoInt(fsync, fd);
+}
+
+int fdatasyncNoInt(int fd) {
+  return wrapNoInt(fdatasync, fd);
+}
+
 ssize_t readNoInt(int fd, void* buf, size_t count) {
   return wrapNoInt(read, fd, buf, count);
 }

folly/FileUtil.h

@@ -31,6 +31,8 @@ namespace folly {
  * semantics of underlying system calls.
  */
 int closeNoInt(int fd);
+int fsyncNoInt(int fd);
+int fdatasyncNoInt(int fd);
 
 ssize_t readNoInt(int fd, void* buf, size_t n);
 ssize_t preadNoInt(int fd, void* buf, size_t n, off_t offset);