Check default warnings

__END__
# default warnings should be displayed if you don't add anything
# optional shouldn't
my $a = oct "7777777777777777777777777777777777779" ;
EXPECT
Integer overflow in octal number at - line 3.
########
# no warnings should be displayed 
no warnings ;
my $a = oct "7777777777777777777777777777777777778" ;
EXPECT
########
# all warnings should be displayed 
use warnings ;
my $a = oct "7777777777777777777777777777777777778" ;
EXPECT
Integer overflow in octal number at - line 3.
Illegal octal digit '8' ignored at - line 3.
Octal number > 037777777777 non-portable at - line 3.
########
# check scope
use warnings ;
my $a = oct "7777777777777777777777777777777777778" ;
{
    no warnings ;
    my $a = oct "7777777777777777777777777777777777778" ;
}    
my $c = oct "7777777777777777777777777777777777778" ;
EXPECT
Integer overflow in octal number at - line 3.
Illegal octal digit '8' ignored at - line 3.
Octal number > 037777777777 non-portable at - line 3.
Integer overflow in octal number at - line 8.
Illegal octal digit '8' ignored at - line 8.
Octal number > 037777777777 non-portable at - line 8.
########
# all warnings should be displayed 
use warnings ;
my $a = oct "0xfffffffffffffffffg" ;
EXPECT
Integer overflow in hexadecimal number at - line 3.
Illegal hexadecimal digit 'g' ignored at - line 3.
Hexadecimal number > 0xffffffff non-portable at - line 3.
########
# all warnings should be displayed 
use warnings ;
my $a = oct "0b111111111111111111111111111111111111111111111111111111111111111112";
EXPECT
Integer overflow in binary number at - line 3.
Illegal binary digit '2' ignored at - line 3.
Binary number > 0b11111111111111111111111111111111 non-portable at - line 3.
