wolfssl/wolfcrypt/wc_port.h: add WOLFSSL_API attribute to wolfSSL_Atomic_Int_Init, wolfSSL_Atomic_Int_FetchAdd, and wolfSSL_Atomic_Int_FetchAdd, and add fallback definitions for them, allowing elimination of SINGLE_THREADED implementations of wolfSSL_Ref*(), and allowing ungated use of wolfSSL_Atomic_* calls in api.c.

wolfcrypt/src/dh.c: in wc_DhAgree_ct(), remove frivolous XMEMSET() and stray semicolon.

wolfcrypt/benchmark/benchmark.c: fix bench_rsaKeyGen() to skip tests of key sizes below RSA_MIN_SIZE, and add 4096 bit benchmark if RSA_MAX_SIZE is big enough.

tests/unit.h:
* adopt definitions of TEST_FAIL, TEST_SUCCESS, and TEST_SKIPPED from unit.c, remap TEST_SKIPPED from -7777 to 3, and add TEST_SUCCESS_NO_MSGS, TEST_SKIPPED_NO_MSGS, EXPECT_DECLS_NO_MSGS(), and EXPECT_FAILURE_CODEPOINT_ID, to support existing and future expected-particular-failure test cases without log noise.
* rename outer gate from CyaSSL_UNIT_H to TESTS_UNIT_H.

tests/api.c:
* use EXPECT_DECLS_NO_MSGS() in test_ssl_memio_setup(), test_ssl_memio_read_write(), and test_wolfSSL_client_server_nofail_memio(), and globally update affected expected error codes to correspond.
* use atomics for {client,server}SessRemCount{Malloc,free} to fix races in SessRemCtxCb() and SessRemSslSetupCb().

…deref reported by clang-tidy in FIPS/Async configs.

wolfssl/internal.h: add DTLS13_HANDSHAKE_HEADER_SZ;

src/tls13.c: in EchHashHelloInner(), use falseHeader[DTLS13_HANDSHAKE_HEADER_SZ] to fix buffer overrun;

src/dtls13.c: add static assert for DTLS13_HANDSHAKE_HEADER_SZ.

…itions, and add static_assert2().

…d ecc_sets_count using accessor functions, to fix linker relocation errors in Fedora packaging test.

…edora packaging test: always export ECC_API functions, but when !WOLFSSL_PUBLIC_ECC_ADD_DBL, remap them with wc_ prefixes.

…ors in Fedora packaging test: always export ECC_API functions, but when !WOLFSSL_PUBLIC_ECC_ADD_DBL, remap them with wc_ prefixes."

This reverts commit a31e914.

…kaging tests.