Clean up OatFile.

In Setup(), avoid reading beyond the end and use the %zu
format specifier instead of %zd for size_t output.

Make the .bss section pointers non-const.

Change-Id: Ic8f066effe8037b552d8e911c6a5d17370d79ff4
diff --git a/compiler/oat_writer.h b/compiler/oat_writer.h
index a82d09e..d6cb65b 100644
--- a/compiler/oat_writer.h
+++ b/compiler/oat_writer.h
@@ -281,7 +281,7 @@
 
   // Offsets of the dex cache arrays for each app dex file. For the
   // boot image, this information is provided by the ImageWriter.
-  SafeMap<const DexFile*, size_t> dex_cache_arrays_offsets_;
+  SafeMap<const DexFile*, size_t> dex_cache_arrays_offsets_;  // DexFiles not owned.
 
   // Offset of the oat data from the start of the mmapped region of the elf file.
   size_t oat_data_offset_;