Add command to run Python scripts with the current interpreter.

mesonbuild/mesonmain.py

@@ -303,6 +303,12 @@ def run(args, mainfile=None):
             return mconf.run(remaining_args)
         elif cmd_name == 'wrap':
             return wraptool.run(remaining_args)
+        elif cmd_name == 'runpython':
+            import runpy
+            script_file = remaining_args[0]
+            sys.argv[1:] = remaining_args[1:]
+            runpy.run_path(script_file, run_name='__main__')
+            sys.exit(0)
 
     # No special command? Do the basic setup/reconf.
     if len(args) >= 2 and args[0] == '--internal':