FindOpenSSL does not find lib64 libraries in custom prefix on Ubuntu

When user wants to build against custom openssl-3.0 (or openssl git master) installation and set -DOPENSSL_ROOT_DIR= pointing to the custom openssl installation root (prefix), on x86_64 platform — FindOpenSSL unable to detect this installation correctly (and finds system libraries instead), because it considers only lib dir in find_library, but not lib64. (That's how I understood it).

Tested on cmake 3.20.2 (built from git) on Ubuntu 18.04.

For example, person builds gost-engine while previously installed openssl-3 into /opt/openssl-gost.

root@bionic:/opt/openssl/gost-engines/build# rm CMakeCache.txt; strace -f -o a cmake -DCMAKE_BUILD_TYPE=Release -DOPENSSL_ROOT_DIR=/opt/openssl-gost -DOPENSSL_ENGINES_DIR=/opt/openssl-gost/lib64/engines-3 -DOPENSSL_LIBRARIES=/opt/openssl-gost/lib64  ..
...
-- Found OpenSSL: /usr/lib/x86_64-linux-gnu/libcrypto.so (found suitable version "3.1.0", minimum required is "3.0")
-- Found OpenSSL application: /opt/openssl-gost/bin/openssl

This is incorrect library. strace shows it considers only lib and not lib64:

root@bionic:/opt/openssl/gost-engines/build# grep /opt/openssl-gost/lib a
27574 stat("/opt/openssl-gost/lib", 0x7ffe0d828770) = -1 ENOENT (No such file or directory)
27574 openat(AT_FDCWD, "/opt/openssl-gost/lib", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = -1 ENOENT (No such file or directory)
27574 stat("/opt/openssl-gost/lib", 0x7ffe0d828770) = -1 ENOENT (No such file or directory)
27574 stat("/opt/openssl-gost/lib", 0x7ffe0d828770) = -1 ENOENT (No such file or directory)
27574 stat("/opt/openssl-gost/lib", 0x7ffe0d828770) = -1 ENOENT (No such file or directory)

Even if I pass -DFIND_LIBRARY_USE_LIB64_PATHS=1 it does not start to look into lib64.

Passing -DCMAKE_FIND_LIBRARY_CUSTOM_LIB_SUFFIX=64 helps to find correct library:

root@bionic:/opt/openssl/gost-engines/build# rm CMakeCache.txt; strace -f -o a cmake -DCMAKE_BUILD_TYPE=Release -DOPENSSL_ROOT_DIR=/opt/openssl-gost -DOPENSSL_ENGINES_DIR=/opt/openssl-gost/lib64/engines-3 -DOPENSSL_LIBRARIES=/opt/openssl-gost/lib64 -DCMAKE_FIND_LIBRARY_CUSTOM_LIB_SUFFIX=64 ..
...
-- Found OpenSSL: /opt/openssl-gost/lib64/libcrypto.so (found suitable version "3.1.0", minimum required is "3.0")
-- Found OpenSSL application: /opt/openssl-gost/bin/openssl
...