Log Message:
blosc: updated to 1.21.2

Changes from 1.21.1 to 1.21.2
=============================

* Add support for SHUFFLE_AVX2_ENABLED and SHUFFLE_SSE2_ENABLED
  even if AVX2 or SSE2 is not available.  See PR #347. Thanks to
  Thomas VINCENT.

* Upgrade internal-complib zstd from 1.5.0 to 1.5.2.  Thanks to
  Mark Kittisopikul.

* Many small code improvements, improved consistency and typo fixes.
  Thanks to Dimitri Papadopoulos Orfanos.

* New HIDE_SYMBOLS CMake option to control the symbols exposure.
  Default is ON.  Thanks to Mariusz Zaborski.