Merge commit '5502bd66bb97' from llvm.org/master into apple/main

Author: git apple-llvm automerger

compiler-rt/lib/profile/GCDAProfiling.c

@@ -303,16 +303,11 @@ static void unmap_file() {
 
   mmap_handle = NULL;
 #else
-  if (msync(write_buffer, file_size, MS_SYNC) == -1) {
+  if (munmap(write_buffer, file_size) == -1) {
     int errnum = errno;
-    fprintf(stderr, "profiling: %s: cannot msync: %s\n", filename,
+    fprintf(stderr, "profiling: %s: cannot munmap: %s\n", filename,
             strerror(errnum));
   }
-
-  /* We explicitly ignore errors from unmapping because at this point the data
-   * is written and we don't care.
-   */
-  (void)munmap(write_buffer, file_size);
 #endif
 
   write_buffer = NULL;