Add projects/firefox/get-moz-build-date

#!/usr/bin/perl -w

# Generate a MOZ_BUILD_DATE based on firefox version number

use strict;

my ($year) = split('-', `git show -s --format='%ci'`);

if ($? != 0) {

    print STDERR "Failed to get year from the git commit\n";

    print "exit 1\n";

    exit 1;

}

die "missing argument" unless @ARGV;

my $version = $ARGV[0];

$version =~ s/\D+$//;

my @v = split(/[\.ab]/, $version);

push @v, '0' if @v < 4;

push @v, '0' if @v < 4;

my $day_of_month = int(($v[0] - 45) / 5);

my $date = 101010101 + $year * 10000000000 + $day_of_month * 1000000

           + $v[1] * 10000 + $v[2] * 100 + $v[3];

$date += 100000000 unless $version =~ m/[ab]/;

print "export MOZ_BUILD_DATE=$date\n";