perlasm/x86_64-xlate.pl: handle binary constants early.

Not all assemblers of "gas" flavour handle binary constants, e.g.
seasoned MacOS Xcode doesn't, so give them a hand.

(Imported from upstream's ba26fa14556ba49466d51e4d9e6be32afee9c465.)

Change-Id: I35096dc8035e06d2fbef2363b869128da206ff9d
Reviewed-on: https://boringssl-review.googlesource.com/7459
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
diff --git a/crypto/perlasm/x86_64-xlate.pl b/crypto/perlasm/x86_64-xlate.pl
index 79c3c03..4965985 100755
--- a/crypto/perlasm/x86_64-xlate.pl
+++ b/crypto/perlasm/x86_64-xlate.pl
@@ -190,6 +190,7 @@
     sub out {
     	my $self = shift;
 
+	$self->{value} =~ s/\b(0b[0-1]+)/oct($1)/eig;
 	if ($gas) {
 	    # Solaris /usr/ccs/bin/as can't handle multiplications
 	    # in $self->{value}
@@ -200,7 +201,6 @@
 	    }
 	    sprintf "\$%s",$self->{value};
 	} else {
-	    $self->{value} =~ s/(0b[0-1]+)/oct($1)/eig;
 	    $self->{value} =~ s/0x([0-9a-f]+)/0$1h/ig if ($masm);
 	    sprintf "%s",$self->{value};
 	}