Catch "Misplaced _ in number" warnings from 5.6

If a Test::Warn dep isn't acceptable, the offending tests could be
skipped on 5.6 instead.

Author: tsibley

Makefile.PL

@@ -40,6 +40,7 @@ requires 'Storable'    => '2.17';
 test_requires 'Class::Inspector' => '1.22';
 test_requires 'File::Remove'     => '1.42';
 test_requires 'Test::More'       => '0.86';
+test_requires 'Test::Warn'       => '0.30';
 test_requires 'Test::Object'     => '0.07';
 test_requires 'Test::SubCalls'   => '1.07';
 test_requires 'Test::Deep';

t/07_token.t

@@ -4,7 +4,7 @@
 
 use lib 't/lib';
 use PPI::Test::pragmas;
-use Test::More tests => 570 + ($ENV{AUTHOR_TESTING} ? 1 : 0);
+use Test::More tests => ($] >= 5.006 and $] < 5.008 ? 570 : 568) + ($ENV{AUTHOR_TESTING} ? 1 : 0);
 
 use File::Spec::Functions ':ALL';
 use PPI;
@@ -100,7 +100,13 @@ SCOPE: {
 
 		if ($base != 256) {
 			$^W = 0;
-			my $literal = eval $code;
+			my $literal;
+			if ( $] >= 5.006 and $] < 5.008 and $code =~ /^1_0[.]?$/ ) {
+				warning_is { $literal = eval $code } "Misplaced _ in number",
+					"$] warns about misplaced underscore";
+			} else {
+				$literal = eval $code;
+			}
 			if ($@) {
 				is($token->literal, undef, "literal('$code'), $@");
 			} else {