remove triple flag

Author: finagolfin

Utilities/bootstrap

@@ -144,9 +144,6 @@ def add_build_args(parser):
         dest="cross_compile_hosts",
         help="List of cross compile hosts targets.",
         default=[])
-    parser.add_argument(
-        "--cross-compile-target-triple",
-        help="Swift cross-compilation target triple")
     parser.add_argument(
         "--cross-compile-config",
         help="Swift flags to cross-compile SPM with itself")
@@ -285,11 +282,12 @@ def get_ninja_path(args):
         return call_output(["which", "ninja"], verbose=args.verbose)
 
 def get_build_target(args, cross_compile=False):
-    """Returns the target-triple of the current machine."""
+    """Returns the target-triple of the current machine or for cross-compilation."""
     try:
         command = [args.swiftc_path, '-print-target-info']
         if cross_compile:
-            command += ['-target', args.cross_compile_target_triple]
+            cross_compile_json = json.load(open(args.cross_compile_config))
+            command += ['-target', cross_compile_json["target"]]
         target_info_json = subprocess.check_output(command,
                                stderr=subprocess.PIPE, universal_newlines=True).strip()
         args.target_info = json.loads(target_info_json)