Lexical subroutine doesn't return correct name

[nanto]

PPI can parse lexical subroutines but its name is incorrect. Run the following code:

use PPI;
use feature qw(say);

my $doc = PPI::Document->new(\'my sub foo {}');
say $doc->schild(0)->name;

Actual output: sub

Expected output: foo

[nanto]

This problem causes Perl-Critic's problem Perl-Critic/Perl-Critic#955.

[oalders]

Fixed via #261