no class for non-scalar types < 5.12

<5.12 errors: (coretypes not ready yet)
Can't declare class for non-scalar @buckets in "my" at lib/Perfect/Hash/HanovPP.pm line 53, near "my str @buckets"
Can't declare class for non-scalar @G in "my" at lib/Perfect/Hash/HanovPP.pm line 56, near "my int @G"
Can't declare class for non-scalar %slots in "my" at lib/Perfect/Hash/HanovPP.pm line 73, near "my int %slots"

also add pod for -hash=name