bootstrap: force target on Darwin

Author: compnerd

Utilities/bootstrap

@@ -742,6 +742,7 @@ def build_swiftpm_with_cmake(args):
 
     if platform.system() == 'Darwin':
         cmake_flags.append("-DCMAKE_C_FLAGS=-target %s%s" % (get_build_target(args), g_macos_deployment_target))
+        cmake_flags.append("-DCMAKE_Swift_FLAGS=-target %s%s" % (get_build_target(args), g_macos_deployment_target))
         cmake_flags.append("-DCMAKE_OSX_DEPLOYMENT_TARGET=%s" % g_macos_deployment_target)
 
     build_with_cmake(args, cmake_flags, ["swift-bootstrap", "PackageDescription", "PackagePlugin", "CompilerPluginSupport"], args.project_root, args.bootstrap_dir)