WOLFSSL_SS_* small stack macro compress

[effbiae]

Description

There are many lines of small stack conditional compiles (#ifdef WOLFSSL_SMALL_STACK) that can be compressed to fewer lines using the macros introduced in this PR.

I've compressed src/ssl_load.c by hand resulting in a net 100 line deletion in the code base. I hope to automate some of the rest of the work which I can do in stages, if that suits.

I considered calling the macros WOLFSSL_SMALL_STACK_*, but the names became quite long.

Testing

./configure --enable-all && make check && \
./configure --enable-all CFLAGS=-DWOLFSSL_SMALL_STACK && make check && \
./configure --enable-all CFLAGS="-DWOLFSSL_SMALL_STACK -DWOLFSSL_CHECK_MEM_ZERO" && make check

[wolfSSL-Bot]

Can one of the admins verify this patch?

[effbiae]

i don't think these failures are related to the PR:

• regarding the Espressif latest docker build error, i think the compiler might think thread_local is a keyword (it's a keyword in C++ since C++11)
• and the socat failure disappeared when i turned on the socat workflow on my github repo

[dgarske]

We actually have a pattern for this all ready. See wolfssl/wolfcrypt/types.h WC_DECLARE_VAR, WC_ALLOC_VAR, WC_FREE_VAR and WC_DECLARE_ARRAY, WC_ALLOC_ARRAY, WC_FREE_ARRAY
You are welcome to refactor these to use the existing helpers. However there are many places we do this small stack pattern, so I am also fine if you want to close this PR.

[effbiae]

superseded by #9153