relative rpath for librdkafka links

Author: dzuelke

support/build/extensions/no-debug-non-zts-20180731/rdkafka

@@ -17,4 +17,8 @@ esac
 
 CONFIGURE_EXTRA="--with-rdkafka=${OUT_PREFIX}"
 
+from_ext_to_lib=$(realpath --relative-to="$(php-config --extension-dir)" "${OUT_PREFIX}/lib")
+
+MAKE_EXTRA="LDFLAGS=${LDFLAGS:--Wl},-rpath='\$\$ORIGIN/${from_ext_to_lib}'"
+
 source $(dirname $BASH_SOURCE)/../pecl

support/build/extensions/pecl

@@ -29,7 +29,8 @@ phpize
 ./configure \
 	--prefix=${OUT_PREFIX} \
 	${CONFIGURE_EXTRA:-}
-make -s -j $(($(nproc)+1))
+make -s -j $(($(nproc)+1)) \
+	${MAKE_EXTRA:-}
 
 # php was a build dep, and it's in $OUT_PREFIX; we only want our build results in the final archive, and no build deps
 # the easiest way is to nuke $OUT_PREFIX and running "make install", but extensions built for PHP 8.1+ need PHP headers during linking