Work around broken largefile on older android

Apparently requesting 64-bit file support on Android
api versions prior to 24 results in missing `ftello()`
and `fseeko()` declarations and other problems.

The idea of this fix is to just limit such builds to
32-bit files.

Change contributed by Vy Nguyen, originally in
#17

Author: rillian

src/internal.h

@@ -18,14 +18,17 @@
 # if !defined(_GNU_SOURCE)
 #  define _GNU_SOURCE
 # endif
-# if !defined(_LARGEFILE_SOURCE)
-#  define _LARGEFILE_SOURCE
-# endif
-# if !defined(_LARGEFILE64_SOURCE)
-#  define _LARGEFILE64_SOURCE
-# endif
-# if !defined(_FILE_OFFSET_BITS)
-#  define _FILE_OFFSET_BITS 64
+/* 64-bit file access is broken before ANDROID 24. */
+# if !defined(__ANDROID__) || __ANDROID_API__ >= 24
+#  if !defined(_LARGEFILE_SOURCE)
+#   define _LARGEFILE_SOURCE
+#  endif
+#  if !defined(_LARGEFILE64_SOURCE)
+#   define _LARGEFILE64_SOURCE
+#  endif
+#  if !defined(_FILE_OFFSET_BITS)
+#   define _FILE_OFFSET_BITS 64
+#  endif
 # endif
 
 # include <stdlib.h>