MacPlatform: use install_name_tool to add /usr/local/lib and /opt/hombrew/lib to rpath of lime.ndll

Previously, we added these rpaths to lime.ndll when it was built in commits c70ec9f and 333d093, but it's actually necessary only for Neko, so now I made it happen specfically after calling `nekotools boot` to create the Neko executable.

I've tested cpp and hl, and I've confirmed that the executables still launch successfully when these rpaths are omitted. It's better for their security to use fewer rpaths.

As noted commit c70ec9f, adding these rpaths is necessary due to a change in Xcode 15 where /usr/local/lib used to be available on the rpath automatically, but now it isn't, which affects the executable's ability to find the libneko dylib.

Author: joshtynjala

project/Build.xml

@@ -442,13 +442,6 @@
 			</section>
 
 			<section if="mac">
-				<!--
-					starting in xcode 15, rpath doesn't automatically include
-					/usr/local/lib, but we need it for neko
-				-->
-				<vflag name="-rpath" value="/usr/local/lib" />
-				<vflag name="-rpath" value="/opt/homebrew/lib" if="HXCPP_ARM64"/>
-
 				<vflag name="-l" value="iconv" />
 				<vflag name="-framework" value="IOKit" />
 				<vflag name="-framework" value="Foundation" />

tools/platforms/MacPlatform.hx

@@ -2,6 +2,7 @@ package;
 
 import lime.tools.HashlinkHelper;
 import hxp.Haxelib;
+import hxp.HostArchitecture;
 import hxp.HXML;
 import hxp.Log;
 import hxp.Path;
@@ -188,6 +189,17 @@ class MacPlatform extends PlatformTarget
 
 			NekoHelper.createExecutable(project.templatePaths, "mac" + dirSuffix.toLowerCase(), targetDirectory + "/obj/ApplicationMain.n", executablePath);
 			NekoHelper.copyLibraries(project.templatePaths, "mac" + dirSuffix.toLowerCase(), executableDirectory);
+
+			// starting in xcode 15, rpath doesn't automatically include
+			// /usr/local/lib, but we need it for libneko dylib
+			System.runCommand("", "install_name_tool", ["-add_rpath", "/usr/local/lib", Path.join([executableDirectory, "lime.ndll"])]);
+			if (System.hostArchitecture == HostArchitecture.ARM64)
+			{
+				// on Apple Silicon, the user may have installed Neko with
+				// Homebrew, which has a different path. however, if the
+				// Homebrew path doesn't exist, that's okay.
+				System.runCommand("", "install_name_tool", ["-add_rpath", "/opt/homebrew/lib", Path.join([executableDirectory, "lime.ndll"])]);
+			}
 		}
 		else if (targetType == "hl")
 		{