scripts: update gcc-wrapper to python3

#! /usr/bin/env python2

#! /usr/bin/env python3

# SPDX-License-Identifier: GPL-2.0-only

# Copyright (c) 2011-2017, 2018 The Linux Foundation. All rights reserved.

warning_re = re.compile(r'''(.*/|)([^/]+\.[a-z]+:\d+):(\d+:)? warning:''')

def interpret_warning(line):

    """Decode the message from gcc.  The messages we care about have a filename, and a warning"""

    line = line.rstrip('\n')

    line = line.rstrip().decode()

    m = warning_re.match(line)

    if m and m.group(2) not in allowed_warnings:

        print "error, forbidden warning:", m.group(2)

        print("error, forbidden warning:", m.group(2))

        # If there is a warning, remove any object if it exists.

        if ofile:

    try:

        proc = subprocess.Popen(args, stderr=subprocess.PIPE)

        for line in proc.stderr:

            print line,

            print(line, end=' ')

            interpret_warning(line)

        result = proc.wait()

    except OSError as e:

        result = e.errno

        if result == errno.ENOENT:

            print args[0] + ':',e.strerror

            print 'Is your PATH set correctly?'

            print(args[0] + ':',e.strerror)

            print('Is your PATH set correctly?')

        else:

            print ' '.join(args), str(e)

            print(' '.join(args), str(e))

    return result