libjpeg-turbo: update 1.4.1 -> 1.4.2

https://github.com/libjpeg-turbo/libjpeg-turbo/blob/1.4.2/ChangeLog.txt



  1.4.2
  =====

  [1] Fixed an issue whereby cjpeg would segfault if a Windows bitmap with a
  negative width or height was used as an input image (Windows bitmaps can have
  a negative height if they are stored in top-down order, but such files are
  rare and not supported by libjpeg-turbo.)

  [2] Fixed an issue whereby, under certain circumstances, libjpeg-turbo would
  incorrectly encode certain JPEG images when quality=100 and the fast integer
  forward DCT were used.  This was known to cause 'make test' to fail when the
  library was built with '-march=haswell' on x86 systems.

  [3] Fixed an issue whereby libjpeg-turbo would crash when built with the latest
  & greatest development version of the Clang/LLVM compiler.  This was caused by
  an x86-64 ABI conformance issue in some of libjpeg-turbo's 64-bit SSE2 SIMD
  routines.  Those routines were incorrectly using a 64-bit mov instruction to
  transfer a 32-bit JDIMENSION argument, whereas the x86-64 ABI allows the upper
  (unused) 32 bits of a 32-bit argument's register to be undefined.  The new
  Clang/LLVM optimizer uses load combining to transfer multiple adjacent 32-bit
  structure members into a single 64-bit register, and this exposed the ABI
  conformance issue.

  [4] Fixed a bug in the MIPS DSPr2 4:2:0 "plain" (non-fancy and non-merged)
  upsampling routine that caused a buffer overflow (and subsequent segfault) when
  decompressing a 4:2:0 JPEG image whose scaled output width was less than 16
  pixels.  The "plain" upsampling routines are normally only used when
  decompressing a non-YCbCr JPEG image, but they are also used when decompressing
  a JPEG image whose scaled output height is 1.

  [5] Fixed various negative left shifts and other issues reported by the GCC and
  Clang undefined behavior sanitizers.  None of these was known to pose a
  security threat, but removing the warnings makes it easier to detect actual
  security issues, should they arise in the future.

Signed-off-by: Andre McCurdy <armccurdy@gmail.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>