Memory allocator code cleanup

Memory allocator code cleanup

Typedefs of CRYPTO malloc, realloc and free.

MEM_CHECK "modes" are used only as a CRYPTO_mem_ctrl() parameter

The CRYPTO_mem_ctrl is defined only if OPENSSL_NO_CRYPTO_MDEBUG is
defined, thus define the MEM_CHECK modes under the same condition.

Maybe the macros can be removed at all since:
1. CRYPTO_mem_ctrl() just returns -1 and ignores the parameter
2. CRYPTO_mem_ctr() is declared as DEPRECATED by 3.0

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/11042)