v20.08 release

* Bug fixes
  * strcmp-mte nul check
  * strncmp-mte with large size
  * arm memcpy with large size (CVE-2020-6096)
* String routines performance improvements
  * strlen
  * memmove with backward copy
* Benchmarking code for strings and memory routines
  * strlen

README

@@ -9,7 +9,7 @@ contributor-agreement.pdf. This is needed so upstreaming code
 to projects that require copyright assignment is possible.
 
 Regular quarterly releases are tagged as vYY.MM, the latest
-release is v20.05.
+release is v20.08.
 
 Source code layout: