Update libjpeg-turbo to v2.0.90 (2.1 beta1)

Update Chromium's copy of libjpeg-turbo to the latest upstream
release (v2.0.90) and re-apply our local changes documented in
README.chromium.

Cherry-pick two additional changes from upstream to fix bugs found
by fuzzers:
1) https://github.com/libjpeg-turbo/libjpeg-turbo/commit/ccaba5d7894ecfb5a8f11e48d3f86e1f14d5a469
2) https://github.com/libjpeg-turbo/libjpeg-turbo/commit/c7ca521bc85b57d41d3ad4963c13fc0100481084

Significant changes provided by this update:
1) A large performance boost to JPEG encoding due to an improved
   Huffman encoding implementation.
2) The complete removal of Arm Neon assembly code. This allows Arm's
   control-flow integrity security features (Armv8.3-A Pointer
   Authentication and Armv8.5-A Branch Target Identification) to be
   switched on with the appropriate compiler flags.

Bug: 922430
Bug: b/135180511
Bug: 919548, 1145581
Change-Id: I319fcdc55b3fd5b219425c07a4e4a03587f4e06d
diff --git a/jconfig.h b/jconfig.h
index e839580..f63fb52 100644
--- a/jconfig.h
+++ b/jconfig.h
@@ -4,10 +4,10 @@
 #define JPEG_LIB_VERSION 62
 
 /* libjpeg-turbo version */
-#define LIBJPEG_TURBO_VERSION 2.0.1
+#define LIBJPEG_TURBO_VERSION 2.0.90
 
 /* libjpeg-turbo version in integer form */
-#define LIBJPEG_TURBO_VERSION_NUMBER  2000001
+#define LIBJPEG_TURBO_VERSION_NUMBER 2000090
 
 /* Support arithmetic encoding */
 /* #define C_ARITH_CODING_SUPPORTED 1 */
@@ -30,7 +30,7 @@
  * We do not support run-time selection of data precision, sorry.
  */
 
-#define BITS_IN_JSAMPLE  8      /* use 8 or 12 */
+#define BITS_IN_JSAMPLE 8      /* use 8 or 12 */
 
 /* Define to 1 if you have the <locale.h> header file. */
 #define HAVE_LOCALE_H 1
@@ -61,11 +61,6 @@
    unsigned. */
 /* #undef RIGHT_SHIFT_IS_UNSIGNED */
 
-/* Define to 1 if type `char' is unsigned and you are not using gcc.  */
-#ifndef __CHAR_UNSIGNED__
-/* # undef __CHAR_UNSIGNED__ */
-#endif
-
 /* Define to empty if `const' does not conform to ANSI C. */
 /* #undef const */