libjpeg-turbo: Upgrade to 1.5.1

The changes from 1.4.2 to 1.5.1 include
a big amount of fixes and huge performance improvements.
As highlights there is a full ARM 64-bit (ARMv8) NEON SIMD
implementation which improves compression of full-color JPEGs
by about 2-2.5x on average on Cortex-A53 and Cortex-A57 cores.
Also  SIMD acceleration for Huffman encoding on NEON-capable
ARM 32-bit and 64-bit platforms was added.
Performance on x86/x86_64 was also improved by
adding better optimized SSE2 routines.

For the full changelog, please see the ChangeLog.md
file.

Partial decoding optimizations, the security fix
to adress b/27494207 and the fix for the AARCH64
conformance issueare present in the release.
The README.android file was edited to reflect this.

The configuration files were regenerated
and all Android specific changes were applied.

BUG:28268702

Change-Id: I538291d894df1da01d3f733771647df1fb61ec42
Signed-off-by: Alex Naidis <alex.naidis@linux.com>
diff --git a/jchuff.h b/jchuff.h
index d49a992..4236089 100644
--- a/jchuff.h
+++ b/jchuff.h
@@ -5,7 +5,8 @@
  * Copyright (C) 1991-1997, Thomas G. Lane.
  * It was modified by The libjpeg-turbo Project to include only code relevant
  * to libjpeg-turbo.
- * For conditions of distribution and use, see the accompanying README file.
+ * For conditions of distribution and use, see the accompanying README.ijg
+ * file.
  *
  * This file contains declarations for Huffman entropy encoding routines
  * that are shared between the sequential encoder (jchuff.c) and the
@@ -39,4 +40,4 @@
 
 /* Generate an optimal table definition given the specified counts */
 EXTERN(void) jpeg_gen_optimal_table
-        (j_compress_ptr cinfo, JHUFF_TBL * htbl, long freq[]);
+        (j_compress_ptr cinfo, JHUFF_TBL *htbl, long freq[]);