Log Message:
zstd: updated to 1.4.3

Zstandard v1.4.3

Dictionary Compression Regression
We discovered an issue in the v1.4.2 release, which can degrade the \ 
effectiveness of dictionary compression. This release fixes that issue.

Detailed Changes
* bug: Fix Dictionary Compression Ratio Regression
* bug: Fix Buffer Overflow in v0.3 Decompression
* build: Add support for IAR C/C++ Compiler for Arm
* misc: Add NULL pointer check in util.c by