OpenSSL 1.1.1q doesn't build on Mac

[fmarier]

Error in our of the unit tests:

 test/v3ext.c:201:24: error: implicitly declaring library function 'memcmp' with type 'int (const void *, const void *, unsigned long)' [-Werror,-Wimplicit-function-declaration]
11:57:39          if (!TEST_true(memcmp(ip1->data, ip2->data, ip1->length) <= 0))
11:57:39                         ^
11:57:39  test/v3ext.c:201:24: note: include the header <string.h> or explicitly provide a declaration for 'memcmp'
11:57:39  1 error generated.
11:57:39  make[1]: *** [test/v3ext.o] Error 1

This was fixed upstream but is not yet part of a release.