maintainer-feedback requested: [Bug 268258] security/p5-Crypt-SSLeay: fix build with clang 15

Bugzilla Automation <bugzilla@FreeBSD.org> has asked freebsd-perl (Nobody)
<perl@FreeBSD.org> for maintainer-feedback:
Bug 268258: security/p5-Crypt-SSLeay: fix build with clang 15
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=268258



--- Description ---
During an exp-run for llvm 15 (see bug 265425), it turned out that
security/p5-Crypt-SSLeay failed to build with clang 15:

  SSLeay.xs:159:31: warning: call to undeclared function 'SSLv2_client_method';
ISO C99 and later do not support implicit function declarations
[-Wimplicit-function-declaration]
	      ctx = SSL_CTX_new(SSLv2_client_method());
				^
  SSLeay.xs:159:31: error: incompatible integer to pointer conversion passing
'int' to parameter of type 'const SSL_METHOD *' (aka 'const struct
ssl_method_st *') [-Wint-conversion]
	      ctx = SSL_CTX_new(SSLv2_client_method());
				^~~~~~~~~~~~~~~~~~~~~

This is because SSLeay.xs uses the obsolete define OPENSSL_NO_SSL2 to determine
whether OpenSSL still supports SSLv2. Since this define was removed from
OpenSSL 1.1 and later, define it via CFLAGS instead.