sdl12-compat: cmake: Select NEW policy for CMP0068.

SDL Commits
1 
From 2ddfc6b436e9d306bbe27e9753d0ffdb0a12aca8 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Sat, 11 Dec 2021 17:46:27 -0500
Subject: [PATCH] cmake: Select NEW policy for CMP0068.

(on macOS, don't let RPATH affect install_name.)

Fixes #151.
---
 CMakeLists.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2184809..948eda3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,6 +7,8 @@ project(sdl12_compat
         VERSION 0.0.1
         LANGUAGES C)
 
+cmake_policy(SET CMP0068 NEW)  # on macOS, don't let RPATH affect install_name.
+
 set(SDL12_COMPAT_VERSION_STR "1.2.50")
 
 option(SDL12TESTS "Enable to build SDL-1.2 test programs" ON)