Circle Stdlib Versions Save

• Synced with Circle Step 46.
• Fixed duplicate definition of fcntl().

• Synced with Circle Step 45.3.1.
• Update Mbed TLS to release v2.28.4.

• Synced with Circle Step 45.2.
• Update mbed TLS to release v2.28.3.
• Aligned toolchain version with Circle (ARM Gnu toolchain 12.2.Rel1).

• Synced with Circle Step 45.1.
• Implemented functions that previously returned an error code:
  • getcwd() and chdir()
  • dup(), dup2() and fcntl(... F_DUPFD ...) (Note: Only the F_DUPFD command is implemented for fcntl()!)
  • stat() and fstat()
  • fsync()
  • ftruncate()
  • isatty()

• Synced with Circle Step 45.
• Updated mbed TLS to release v2.28.1.
• Updated GitHub action to fix deprecation warnings.

• Synced with Circle Step 44.5.

• Synced with Circle Step 44.4.1.
• Updated mbed TLS to release v2.16.12.
• New configure command line option --option for specifying additional preprocessor defines consistently across all libraries.

This release replaces the faulty withdrawn release v15.11.

• Synced with Circle Step 44.3.

• Synced with Circle Step 44.2.
• Aligned toolchain version with Circle (gcc 10.3-2021.07).
• Updated Mbed TLS to version 2.16.11.

• Synced with Circle Step 44.1.
• Fixed issue #22 "Bad memmove behavior". This issue was only reproducible with the AArch64 build.