Many string truncation warnings with newer GCC

[jphickey]

Describe the bug
Ubuntu has released 20.04 LTS which includes GCC 9.3.0. When using this compiler it implements a much stricter (and often over-zealous) checking of string ops.

For instance:

In file included from /usr/include/string.h:495,
                 from /home/joe/code/cfecfs/github/cfe/fsw/cfe-core/src/es/cfe_es_cds.c:49:
In function ‘strncpy’,
    inlined from ‘CFE_ES_RegisterCDSEx’ at /home/joe/code/cfecfs/github/cfe/fsw/cfe-core/src/es/cfe_es_cds.c:299:12:
/usr/include/x86_64-linux-gnu/bits/string_fortified.h:106:10: error: ‘__builtin_strncpy’ specified bound 38 equals destination size [-Werror=stringop-truncation]
  106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

To Reproduce
Build code with default config using GCC 9.3.0, with optimization enabled and full warnings.

Expected behavior
Code should build cleanly.

System observed on:
Ubuntu 20.04 LTS 64 bit.

Additional context
Unfortunately GCC warns about ANY construct which MIGHT truncate, even if truncation is anticipated and handled properly in the code. GCC now declares that one is never allowed to truncate anything in a C library string operation, even if you read the manual and coded it correctly per the C spec, it's still wrong to GCC9.

Reporter Info
Joseph Hickey, Vantage Systems, Inc.