Fix library lookup path in the vendored OpenSSL (rbenv#2493)

* Fix library lookup path in the vendored OpenSSL

When a vendored OpenSSL is needed for compiling Ruby, that OpenSSL installation
ends up with its `bin/openssl` executable broken due to not finding "libssl.so"
and "libcrypto.so" in the global load path for libraries. This doesn't seem to
negatively affect the Ruby "openssl" extension, but is a broken OpenSSL install
nevertheless.

This change causes the `bin/openssl` executable and related shared libraries to
be built with an "RPATH" pointing to the "lib" directory of the vendored OpenSSL.

* fix test

Author: mislav

bin/ruby-build

@@ -1215,7 +1215,7 @@ build_package_openssl() {
   [[ "$1" != openssl-1.0.* ]] || nokerberos=1
 
   # Compile a shared lib with zlib dynamically linked.
-  package_option openssl configure --openssldir="$OPENSSLDIR" --libdir="lib" zlib-dynamic no-ssl3 shared ${nokerberos:+no-ssl2 no-krb5}
+  package_option openssl configure --openssldir="$OPENSSLDIR" --libdir="lib" -Wl,-rpath="$OPENSSL_PREFIX_PATH/lib" zlib-dynamic no-ssl3 shared ${nokerberos:+no-ssl2 no-krb5}
 
   # Skip building OpenSSL docs, which is slow.
   local make_target="install_sw install_ssldirs"

test/build.bats

@@ -397,7 +397,7 @@ DEF
   unstub make
 
   assert_build_log <<OUT
-openssl-1.1.1w: [--prefix=${INSTALL_ROOT}/openssl,--openssldir=${INSTALL_ROOT}/openssl/ssl,--libdir=lib,zlib-dynamic,no-ssl3,shared]
+openssl-1.1.1w: [--prefix=${INSTALL_ROOT}/openssl,--openssldir=${INSTALL_ROOT}/openssl/ssl,--libdir=lib,-Wl,-rpath=${INSTALL_ROOT}/openssl/lib,zlib-dynamic,no-ssl3,shared]
 make -j 2
 make install_sw install_ssldirs
 ruby-3.2.0: [--prefix=$INSTALL_ROOT,--with-openssl-dir=$INSTALL_ROOT/openssl,--with-ext=openssl,psych,+] PKG_CONFIG_PATH=${TMP}/install/openssl/lib/pkgconfig