Run the self.exe command in-process with the supplied params.

def _invoke(self, *params):
		"""
		Run the self.exe command in-process with the supplied params.
		"""
		cmd = [self.exe, '-R', self.location] + list(params)
		with reentry.in_process_context(cmd) as result:
			sys.modules['mercurial.dispatch'].run()
		stdout = result.stdio.stdout.getvalue()
		stderr = result.stdio.stderr.getvalue()
		if not result.returncode == 0:
			raise RuntimeError(stderr.strip() or stdout.strip())
		return stdout.decode('utf-8')